CPC · California Plumbing Code
How many fixtures are required (fixture counts and occupant load tables)?
To determine required restroom fixtures, first find the building occupant load, assume a 50% male / 50% female split (unless you have different data), then apply the ratios in Table 422.1 and round any fractional fixtures up; single‑use, family, and accessible fixtures count toward totals and some small‑occupancy exceptions apply (see **§ 422.0**, **§ 422.1**, and **Table 422.1**).
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Plumbing Code requires buildings to be provided with the minimum number of plumbing fixtures shown in Table 422.1, based on the building occupancy and the total occupant load. The baseline calculation uses a 50% male / 50% female split of the total occupant load and then applies the fixture ratios in Table 422.1; fractional results are rounded up to the next whole fixture. See § 422.0 and § 422.1 for the controlling rules and the table that establishes minimum counts.
Calculate required fixtures by: determine occupant load, assume 50% male/50% female (unless a different distribution is justified), apply Table 422.1 fixture ratios, then round any fractions up to the next whole fixture. (See § 422.1.1.)
Requirements in detail
How to determine the starting occupant load
- Determine the total occupant load using the California Building Code (or Table 4‑1 Occupant Load Factor) as referenced by the CPC; Table 422.1 is applied after the occupant load is known. § 422.1 references using the occupant load to select fixtures from Table 422.1.
Basic calculation steps (quick)
- Assume 50% male / 50% female of the total occupant load unless you have reliable distribution data. § 422.1.1.
- Apply the per‑person fixture ratios from Table 422.1 to each sex (or the aggregate for all‑gender fixtures). § 422.1 and Table 422.1.
- If the calculation produces a fractional fixture, round up to the next whole number. For multiple occupancies, sum fractional results for each occupancy first, then round the total up. § 422.1.1.
- All‑gender toilet rooms are counted by calculating the aggregate at 50/50 and using that as the minimum. § 422.1.1.
Substitutions, additions and adjustments
- A water closet may be substituted for each urinal, provided the total number of installed fixtures still complies with Table 422.1. § 422.1.1.
- For very large occupant loads Table 422.1 (and its notes) prescribes additive rules (for example: after certain thresholds add 1 fixture per additional X persons). See the table notes for the specific “add 1 fixture per …” rules. (See Table 422.1 notes.)
Decision‑relevant values (quick reference)
| Decision / threshold | Value or rule | Code Reference |
|---|---|---|
| Default sex split for calculations | 50% male / 50% female | § 422.1.1 |
| Rounding rule | Round any fractional fixture up to next whole fixture; sum fractions across multiple occupancies, then round. | § 422.1.1 |
| All‑gender fixture counting | Aggregate calculated at 50%/50% per Table 422.1 | § 422.1.1 |
| Urinal substitution | A water closet may substitute for each urinal if totals comply with table | § 422.1.1 |
| Small occupancy exceptions | Special exceptions where 1 single‑occupant toilet may serve both sexes for very small loads; see exceptions list. | § 422.0 Exceptions & § 422.2 |
| Primary table of minimum fixtures | Table 422.1 — Minimum Plumbing Facilities (per occupancy type and occupant ranges) | Table 422.1 / § 422.1 |
(Use Table 422.1 to read the specific fixture counts for the occupancy type—assembly, business, mercantile, restaurant, educational, etc.—and the occupant ranges. The table entries list required numbers of water closets, urinals, lavatories, showers/baths and drinking facilities for the ranges shown.)
Exceptions & special cases
- Residential installations are generally excepted from some Table 422.1 requirements; see the exceptions under § 422.0.
- Occupancies with a total occupant load of 10 or less (customers + employees) may use a single‑occupant toilet for both sexes (not adopted for some state agencies—consult the matrix). § 422.0 Exceptions (2).
- Business and mercantile occupancies with a total occupant load of 50 or less may use one single‑occupant toilet for both sexes. § 422.0 Exceptions (3).
- Single‑use, family, or assisted‑use toilet and bathing rooms—when required by other regulations—must be installed per those building regulations and those fixtures do count toward the total required by § 422.1. § 422.1.2.
- Fixtures provided for persons with disabilities must also meet the California Building Code Chapter 11A/11B accessibility provisions (see notes in Table 422.1).
Common mistakes
- Not starting from the correct occupant load (use CBC Table 4‑1 or the Building Code method) before applying Table 422.1. § 422.1 references the occupant load basis.
- Forgetting the 50%/50% default and calculating fixtures using an incorrect gender split. § 422.1.1.
- Rounding down fractional fixtures or rounding per‑occupancy fractions before summing for multiple occupancies (the code requires rounding up and summing fractions across occupancies before rounding). § 422.1.1.
- Omitting single‑use / family / assisted‑use fixtures from the total count when the regulations require them to be provided; they must be included. § 422.1.2.
- Applying exception rules without verifying the applicable adopting agency (some exceptions aren’t adopted for OSHPD, DSA, HCD, etc.). See the CPC adoption matrix and the exception text.
Worked example — assembly theater (practical numbers)
Scenario: New theater (Assembly A‑1) with a calculated total occupant load of 600 persons. Use the default 50/50 split and Table 422.1 for A‑1 fixture requirements. Steps and result:
- Split by sex (default): 300 males / 300 females. § 422.1.1.
- Apply Table 422.1 (A‑1 entries from the table): for 300 males, the table entry for male water closets corresponds to the 201–400 range (which the table lists as 3 water closets for males) and male urinals for the 201–300 range (table shows 2 urinals). For 300 females, the table entry for female water closets in the 201–300 range is 6 water closets. These counts come directly from Table 422.1.
- Totals required (minimum per Table 422.1):
- Male water closets: 3
- Male urinals: 2 (urinals are optional substitution candidates)
- Female water closets: 6
- Lavatories/drinking fountains: per table ranges (apply lavatory and drinking fountain entries for the same occupant ranges; see table).
- Substitution option: you may substitute one water closet for each urinal (i.e., you could install additional water closets instead of urinals) provided the total number of fixtures still meets Table 422.1. § 422.1.1.
Notes: The worked numbers above are taken from the A‑1 row and ranges shown in Table 422.1; always read the exact occupancy row (A‑1, A‑2, B, M, etc.) and the occupant ranges in the official table to determine the precise required counts.
Related provisions
- § 422.0 — Minimum number of required fixtures; exceptions and scope.
- § 422.1 — Fixture count and application of Table 422.1.
- § 422.1.1 — Fixture calculations (50%/50% rule, rounding, all‑gender treatment, urinal substitution).
- § 422.1.2 — Single‑use, family or assisted‑use toilet and bathing facilities (counting toward totals).
- Table 422.1 — Minimum Plumbing Facilities (the primary table listing required water closets, urinals, lavatories, etc., by occupancy and occupant ranges).
Code references
Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:
CPC § 422.1.1 High relevance — show source text
422.1.1 Fixture Calculations. The minimum number of fixtures shall be calculated at 50 percent male and 50 percent female based on the total occupant load. Where information submitted indicates a difference in the distribution
of the sexes such information shall be used to determine the number of fixtures for each sex. Once the occupancy load and occupancy are determined, Table 422.1 shall be applied to determine the minimum number of plumbing fixtures required. Where applying the fixture ratios in Table 422.1 results in fractional numbers, such numbers shall be rounded to the next whole number. For multiple occupancies, fractional numbers shall be first summed and then rounded to the next whole number. For toilet facilities designed for use by all genders, the minimum number of fixtures shall be the aggregate calculated at 50 percent female and 50 percent male in accordance with Table 422.1. Where all-gender fixtures are provided in addition to separate men’s and women’s facilities, those fixtures shall be included in determining the number of fixtures provided in an occupancy. [BSC & DSA-SS] The substitution of a water closet for each urinal shall be permitted provided the total number of fixtures installed complies with Table 422.1. 422.1.2 Single Use, Family or Assisted-Use Toilet, and Bathing Facilities. Where single use, family or assisted-use toilet, and bathing rooms are required, in applicable building regulations, the facilities shall be installed in accordance with those regulations. Fixtures located in single use, family or assisted-use, and bathing room facilities shall contribute to the total number of required fixtures in accordance with Section 422.1.
422.1.3 [DSA-AC] Effective January 1, 1990, in new construction and those existing facilities which occu- pancy type are listed in Tables 422.1 and 4-4 for public use, which apply for permit to undertake construction, structural alterations, repairs or improvement which exceed 50 percent of the square footage of the entire facility, shall install water closets, urinals, lavatories and drinking fountains as stipulated in Tables 422.1 and 4-4 for public use. Community and/or municipal parks with a bleacher capacity not exceeding 500 seats shall be exempt from the requirements of this section and Tables 422.1 and 4-4. Each bathroom shall comply with Part 2, Chapter 11A and 11B of the California Building Code.
422.1.4 [OSHPD 1, 2, 3, 4 & 5] OSHPD facilities shall also comply with requirements of the California Building Code, Sections 1224, 1225, 1226, 1227 and 1228.
422.2 Separate Facilities. Separate toilet facilities shall be provided for each sex.
68 2025 CALIFORNIA PLUMBING CODE
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
PLUMBING FIXTURES AND FIXTURE FITTINGS
CPC § 4.420 High relevance — show source text
410|≥4.420|NA|AHRI
550/590| |Water
source
electri-
cally
operated
positive
displace-
ment|<75|≤0.7885
FL
≤0.6316
IPLV.IP|≤0.7875
FL
≤0.5145
IPLV.IP|75/655|NA|NA|NA|≥3.550|NA|NA|NA|6.150|6.150| |Water
source
electri-
cally
operated
positive
displace-
ment|≥75
and
<150|≤0.7579
FL
≤0.5895
IPLV.IP|≤0.7140
FL
≤0.4620
IPLV.IP|54/445|≥4.640|≥3.680|≥2.680|NA|≥8.330|≥6.410|≥4.420|NA|NA| |Water
source
electri-
cally
operated
positive
displace-
ment|≥75
and
<150|≤0.7579
FL
≤0.5895
IPLV.IP|≤0.7140
FL
≤0.4620
IPLV.IP|75/655|NA|NA|NA|≥3.550|NA|NA|NA|6.150|6.150| |Water
source
electri-
cally
operated
positive
displace-
ment|≥150
and
<300|≤0.6947
FL
≤0.5684
IPLV.IP|≤0.7140
FL
≤0.4620
IPLV.IP|54/445|≥4.640|≥3.680|≥2.680|NA|≥8.330|≥6.410|≥4.420|NA|NA| |Water
source
electri-
cally
operated
positive
displace-
ment|≥150
and
<300|≤0.6947
FL
≤0.5684
IPLV.IP|≤0.7140
FL
≤0.4620
IPLV.IP|75/655|NA|NA|NA|≥3.550|NA|NA|NA|6.150|6.150| |Water
source
electri-
cally
operated
positive
displace-
ment|≥300
and
<600|≤0.6421
FL
≤0.5474
IPLV.IP|≤0.6563
FL
≤0.4305
IPLV.IP|54/445|≥4.930|≥3.960|≥2.970|NA|≥8.900|≥6.California Plumbing Code High relevance — show source text
**
HOURS| |ITEM
CODE|MEMBRANE
THICKNESS|CONSTRUCTION DETAILS|LOAD|TIME|PRE-BMS-92|BMS-92|POST-BMS-92|POST-BMS-92|POST-BMS-92| |F/C-S-34|21/2″|Floor: 2″ reinforced concrete or 2″ precast
reinforced Portland cement concrete or
gypsum slabs, precast slabs to be finished
with1/4″ mortar top coat; ceiling: 2″ precast
reinforced gypsum tile, anchored into
beams with metal ties or clips and covered
with1/2″ 1:3 sanded gypsum plaster.|See
Note 12|4 hrs||1||12–14|4| |F/C-S-35|1″|Floor: 1:3:6 Portland cement, sand and
gravel concrete applied directly to the top of
steel units and 11/2″ thick at top of cells, plus
1/2″ 1:21/2″ cement-sand finish, total thick-
ness at top of cells, 2″; ceiling: 1″ neat
gypsum plaster, back of lath 2″ or more
from underside of cellular steel.|See
Note 15|3 hrs||1||15–18|3| |F/C-S-36|1″|Floor: same as F/C-S-35; ceiling: 1″ gypsum-
vermiculite plaster (ratio of gypsum to
vermiculite 2:1 to 3:1), the back of lath 2″ or
more from under-side of cellular steel.|See
Note 15|4 hrs||1||15–18|4| |F/C-S-37|1″|Floor: same as F/C-S-35; ceiling: 1″ neat
gypsum plaster; back of lath 9″ or more from
underside of cellular steel.|See
Note 15|4 hrs||1||15–18|4| |F/C-S-38|1″|Floor: same as F/C-S-35; ceiling: 1″ gypsum-
vermiculite plaster (ratio of gypsum to
vermiculite 2:1 to 3:1), the back of lath being
9″ or more from underside of cellular steel.|See
Note 15|5 hrs||1||15–18|5| |F/C-S-39|3/4″|Floor: asbestos paper 14 lbs/100 ft2
cemented to steel deck with waterproof
linoleum cement, wood screeds and7/8″
wood floor; ceiling:3/4″ sanded gypsum plas-
ter 1:2 for scratch coat and 1:3 for brown
coat.|See
Note 19|1 hr||1||19–22|1| |F/C-S-40|3/4″|Floor: 11/2″ 1:2:4 Portland cement concrete;
ceiling:3/4″ sanded gypsum plaster 1:2 for
scratch coat and 1:3 for brown coat.CPC § 422.1 High relevance — show source text
** [Not adopted for OSHPD 1, 2, 3, 4 & 5] Each building or structure shall be provided with toilet facilities for employees and customers. Requirements for customers and employees shall be permitted to be met with a single set of restrooms accessible to both groups. Required toilet facilities for employees and customers located in shopping malls or centers shall be permitted to be met by providing a centrally located toilet facility accessible to several stores. The maximum travel distance from entry to any store to the toilet facility shall not exceed 300 feet (91 440 mm). Required toilet facilities for employees and customers in other than shopping malls or centers shall have a maximum travel distance not to exceed 500 feet (152 m).
»
pancy classification shall be determined in accordance with the California Building Code . Occupancy classification not shown in Table 422.1 shall be considered separately by the Authority Having Jurisdiction.
[OSHPD 1, 2, 3, 4 & 5] Plumbing fixtures shall be provided in the minimum number shown in Table 4-2.
Exception: [BSC & DSA-SS] Using occupancy classifica- tion, described as function of space, determine occupant load factor from Table 4-1 Occupant Load Factor, of this chapter.
422.1.1 Fixture Calculations. The minimum number of fixtures shall be calculated at 50 percent male and 50 percent female based on the total occupant load. Where information submitted indicates a difference in the distribution
of the sexes such information shall be used to determine the number of fixtures for each sex. Once the occupancy load and occupancy are determined, Table 422.1 shall be applied to determine the minimum number of plumbing fixtures required. Where applying the fixture ratios in Table 422.1 results in fractional numbers, such numbers shall be rounded to the next whole number. For multiple occupancies, fractional numbers shall be first summed and then rounded to the next whole number. For toilet facilities designed for use by all genders, the minimum number of fixtures shall be the aggregate calculated at 50 percent female and 50 percent male in accordance with Table 422.1. Where all-gender fixtures are provided in addition to separate men’s and women’s facilities, those fixtures shall be included in determining the number of fixtures provided in an occupancy. [BSC & DSA-SS] The substitution of a water closet for each urinal shall be permitted provided the total number of fixtures installed complies with Table 422.1. 422.1.2 Single Use, Family or Assisted-Use Toilet, and Bathing Facilities. Where single use, family or assisted-use toilet, and bathing rooms are required, in applicable building regulations, the facilities shall be installed in accordance with those regulations. Fixtures located in single use, family or assisted-use, and bathing room facilities shall contribute to the total number of required fixtures in accordance with Section 422.1.
CPC § 4.0 High relevance — show source text
0|4.0| |11⁄2 Bathrooms|8.0|5.5| |2 Bathrooms|10.0|6.5| |21⁄2 Bathrooms|11.0|7.5| |3 Bathrooms|12.0|8.0| |Each Additional1⁄2 Bath|0.5|0.5| |Each Additional Bathroom|1.0|1.0| |Bathroom Group (1.6 GPF Flushometer Valve)|3.0|3.0| |Bathroom Group (3.5 GPF Flushometer Valve)|4.0|4.0|
Notes:
1 A bathroom group, for this table, consists of not more than one water closet, up to two lavatories, and either one bathtub or one shower.
2 A half-bath or powder room, for this table, consists of one water closet and one lavatory.
2025 CALIFORNIA PLUMBING CODE 389
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
APPENDIX C
Col1 TABLE C 304.2 BUILDING DRAINS AND BUILDING SEWERS1 Col3 Col4 Col5 DIAMETER
OF PIPE
(inches)MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS DIAMETER
OF PIPE
(inches)SLOPE (inches per foot) SLOPE (inches per foot) SLOPE (inches per foot) SLOPE (inches per foot) DIAMETER
OF PIPE
(inches)1⁄16 1⁄8 1⁄4 1⁄2 2 – – 21 26 21⁄2 – – 24 31 3 – 20 422 502 4 – 180 216 250 5 – 390 480 575 6 – 700 840 1000 8 1400 1600 1920 2300 10 2500 2900 3500 4200 12 3900 4600 5600 6700 15 7000 8300 10 000 12 000 For SI units: 1 inch = 25 mm, 1 inch per foot = 83.3 mm/m
Notes:
1 On-site sewers that serve more than one building shall be permitted to be sized according to the current standards and specifications of the administrative authority for public sewers.
2 A maximum of two water closets or two bathroom groups, except in single-family dwellings, where a maximum of three water closets or three bathroom groups shall be permitted to be installed.
|Col1|TABLE C 304.3 HORIZONTAL FIXTURE
CPC § 101.4.7 High relevance — show source text
Existing 101.4.7 Fire walls 706.1 Height (see Height, Building) 502.1, 503, 504, 505, 508, 510 Occupancy classification Chapter 3 Party walls 706.1.1 Relocatable 3113
Replicable Appendix N Building, Existing 202 Building Department 103 Building Official Duties and powers 103, 104 Qualifications Appendix A Records 104.7
Termination A101.4 Building-Integrated Photovoltaic (BIPV) (see Photovoltaic) Built-Up Roof 1507.10 Business Occupancy (Group B) 303.1.1, 303.1.2, 304 Alarms and detection 907.2.2 Ambulatory care facilities 304, 422 Area 503, 505, 506, 507, 508 Height 503, 504, 505, 508, 510 Higher education laboratories 428, 2702.2
Incidental uses 509 Interior finishes Table 803.13, 804 Live load Table 1607.1 Means of egress Aisles 1018.3
Stairway, exit access 1019 Travel distance 1006.3, 1017.2,
1006.2.1
Mixed occupancies 508.2, 508.3, 508.4 Accessory 303.1.2, 508.2 Ambulatory care facilities 422 Assembly 303.1.2
Assembly spaces 1030 Exit signs 1013.1 Guards 1015.2, 1030.17 Main exit 1030.3
Open air 1005.3.1, 1005.3.2, 1006.3, 1009.6.4, 1019.3, 1027, 1030.6.2 Panic hardware 1010.2.8, 1010.4.1 Smoke-protected 1005.3.1, 1005.3.2, 1006.3, 1009.6.4, 1019.3, 1027, 1030.6.2 Travel distance 1006.2.1, 1006.3, 1017.2, 1030.7 Mixed occupancies 508.3, 508.4 Accessory 508.2 Education 303.1.3
CPC § 420.4 Medium relevance — show source text
420.4 Waste Outlet. Kitchen and laundry sinks shall have a waste outlet and fixture tailpiece not less than 1 [1] ⁄ 2 inches (40 mm) in diameter. Service sinks shall have a waste outlet and fixture tailpiece not less than 2 inches (50 mm) in diameter. Fixture tailpieces shall be constructed from the materials specified in Section 701.2 for drainage piping. Waste outlets shall be provided with an approved strainer.
421.0 Floor Sinks.
421.1 Application. Floor sinks shall comply with ASME A112.6.7.
421.2 Strainers. The waste outlet of a floor sink shall be provided with an approved strainer or grate that is removable and accessible.
422.0 Minimum Number of Required Fixtures. 422.1 Fixture Count. Plumbing fixtures shall be provided for the type of building occupancy and in the minimum number shown in Table 422.1. The total occupant load and occu
TABLE 420.3
COMMERCIAL PRE-RINSE SPRAY VALVE MAXIMUM FLOW RATE
For SI units: 1 gallon per minute = 3.785 L/min, 1 ounce-force = 0.278 N
<
2025 CALIFORNIA PLUMBING CODE 67
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
PLUMBING FIXTURES AND FIXTURE FITTINGS
Exceptions [Not adopted for OSHPD 1, 2, 3, 4 & 5] : (1) Residential installations. (2) In occupancies with a total occupant load of 10 or less, including customers and employees, one toilet facility, designed for use by no more than one person at a time, shall be permitted for use by both sexes. (3) In business and mercantile occupancies with a total occupant load of 50 or less including customers and employees, one toilet facility, designed for use by no more than one person at a time, shall be permitted for use by both sexes. (4) Separate facilities shall not be required where rooms have fixtures designed for use by both sexes and the water closets are installed in privacy compartments. Urinals shall be located in a privacy compartment [BSC & DSA-SS] , as defined, or separate private area and be visually separated from the remainder of the room. Water closet and urinal compartments shall comply with sections 422.6 and 422.7 respectively. 422.2.1 Single Use Facilities. Single use toilet facilities, bathing facilities, and family or assisted use toilet facilities shall be identified with signage indicating use by either sex. 422.2.2 Family or Assisted-Use Toilet Facilities. Where a separate toilet facility is required for each sex, and each toilet facility is required to have only one water closet, two family or assisted-use toilet facilities shall be permitted in place of the required separate toilet facilities. 422.3 Fixture Requirements for Special Occupancies. Additional fixtures shall be permitted to be required where unusual environmental conditions or referenced activities are encountered. In food preparation areas, fixture requirements shall be permitted to be dictated by health codes. 422.3.1 [OSHPD 1, 2, 3, 4, 5 & 6] Separate toilet facil- ities shall be provided for the use of patients, staff per- sonnel and visitors.
CPC § 1.8 Medium relevance — show source text
[HCD 1]**_ The maximum flow rate of kitchen faucets shall not exceed 1.8 gallons (6.81 L) per minute at 60 psi (414 kPa). Kitchen faucets may temporarily increase the flow above the maximum rate, but not to exceed 2.2 gallons (8.32 L) per minute at 60 psi (414 kPa), and must default to a maximum flow rate of 1.8 gallons (6.81 L) per minute at 60 psi (414 kPa) in com- pliance with Chapter 4, Division 4.3 or Chapter 5, Divi- sion 5.3 of the California Green Building Standards Code (CALGreen), as applicable. Note: Where faucets meeting the maximum flow rate of 1.8 gpm (6.81 L) are unavailable, aerators or other means may be used to achieve reduction. 420.3 Pre-Rinse Spray Valve. Commercial food service pre-rinse spray valves shall have a maximum flow rate in accordance with Table 420.3 and shall be equipped with an integral automatic shutoff.
TABLE 420.3
COMMERCIAL PRE-RINSE SPRAY VALVE MAXIMUM FLOW RATE
PRODUCT CLASS BY SPRAY FORCE MAXIMUM FLOW RATE,
GPM
Product Class 1 (≤ 5.0 ounces-force)1.00
Product Class 2 (> 5.0 ounces-force and
≤ 8.0 ounces-force)1.20
Product Class 3 (> 8.0 ounces-force)1.28 For SI units: 1 gallon per minute = 3.785 L/min, 1 ounce-force = 0.278 N
420.4 Waste Outlet. Kitchen and laundry sinks shall have a waste outlet and fixture tailpiece not less than 1 [1] ⁄ 2 inches (40 mm) in diameter. Service sinks shall have a waste outlet and fixture tailpiece not less than 2 inches (50 mm) in diameter. Fixture tailpieces shall be constructed from the materials specified in Section 701.2 for drainage piping. Waste outlets shall be provided with an approved strainer.
421.0 Floor Sinks.
421.1 Application. Floor sinks shall comply with ASME A112.6.7.
421.2 Strainers. The waste outlet of a floor sink shall be provided with an approved strainer or grate that is removable and accessible.
422.0 Minimum Number of Required Fixtures. 422.1 Fixture Count. Plumbing fixtures shall be provided for the type of building occupancy and in the minimum number shown in Table 422.1. The total occupant load and occu
TABLE 420.3
COMMERCIAL PRE-RINSE SPRAY VALVE MAXIMUM FLOW RATE
For SI units: 1 gallon per minute = 3.785 L/min, 1 ounce-force = 0.278 N
<
2025 CALIFORNIA PLUMBING CODE 67
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
PLUMBING FIXTURES AND FIXTURE FITTINGS
Exceptions [Not adopted for OSHPD 1, 2, 3, 4 & 5] : (1) Residential installations.
CPC § 1030.1.1 Medium relevance — show source text
Grandstands 1030.1.1
Mercantile 1018.3, 1018.4 Obstructions 1030.9.6.1
Tables 1030.13.1
Temporary structures 3103.4 Transitions 1030.10
Width 1030.9.1
Alarm Systems, Emergency 908 Alarms, Fire (see Fire Alarm and Smoke Detection Systems) Alarms, Visible 907.5.2.3 Common areas 907.5.2.3.1 Employee work areas 907.5.2.3.1 Group I-1 907.5.2.3.2 Group R-1 907.5.2.3.2 Group R-2 907.5.2.3.3 Public areas 907.5.2.3.1 Alarms, Voice 907.5.2.2 Amusement areas, special 411.3.3, 907.2.13.3
Covered and open mall buildings 402.7.4, 907.2.21 Emergency power 2702.2 High-rise buildings 403.4.4, 907.2.14 Occupant evacuation elevators 3008.9 Underground buildings 405.8.2, 907.2.20 Allowable Stress Design 202 Load combinations 1605, 1605.2 Masonry design 2107 Wood design 2306 Alterations 101.4.7, D103.1 Means of egress 3301.4, 3310.2 Alternating Tread Devices 1011.14 Construction 1011.14.2 Equipment platform 505.3 Heliports 412.7.3 Technical production areas 410.5.3.4 Alternative Materials, Design and Methods 104.2.3, Appendix O Aluminum 1403.5.1, 1604.3.5, Chapter 20 Ambulatory Care Facilities 304.1, 422, Table 509.1, 709.5, Table 1020.3 Emergency and standby power 2702.2 Fire protection and detection 903.2.2.1, 903.3.2, 907.2.2.1 Medical gas systems 427 Smoke compartment 422.2, 422.3, 909.5.3, 1026.4.1 Amusement Area, Special 411 Alarm and detection 411.2, 411.3.3,
907.2.13 Automatic sprinkler system 411.2 Classification 411.1 Emergency voice/alarm communications system 411.3.3, 907.2.13.3 Exit marking 411.4, 411.4.1 Interior finish 411.5
Puzzle room 411.1
CPC § 9.595 Medium relevance — show source text
tonR|COOLING-ONLY
OPERATION
COOLING
EFFICIENCY1
AIR SOURCEEER
(****FL/IPLV), Btu/W·h
WATER SOURCE
POWER INPUT PER
CAPACITY
(FL/IPLV), kW/tonR|COOLING-ONLY
OPERATION
COOLING
EFFICIENCY1
AIR SOURCEEER
(****FL/IPLV), Btu/W·h
WATER SOURCE
POWER INPUT PER
CAPACITY
(FL/IPLV), kW/tonR|HEATING
SOURCE
CONDI-
TIONS
(ENTER-
ING/
LEAVING
WATER)
OR OAT
(db/wb), °F**|LOW|MEDIUM|HIGH|BOOST|LOW|MEDIUM|HIGH|BOOST|BOOST| |EQUIP-
MENT
TYPE|SIZE
CATE-
GORY,
tonR|PATH A|PATH B||105°F|120°F|140°F|140°F|105°F|120°F|140°F|140°F|140°F| |Air
source|All
sizes|≥9.595
FL
≥13.02
IPLV.IP|≥9.215
FL
≥15.01
IPLV.IP|47 db
43 wb4|≥3.290|≥2.770|≥2.310|NA|NA|NA|NA|NA|AHRI
550/590| |Air
source|All
sizes|≥9.595
FL
≥13.30
IPLV.IP|≥9.215
FL
≥15.30
IPLV.IP|17 db
15 wb4|≥2.230|≥1.950|≥1.630|NA|NA|NA|NA|NA|NA| |Water
source
electri-
cally
operated
positive
displace-
ment|<75|≤0.7885
FL
≤0.6316
IPLV.IP|≤0.7875
FL
≤0.5145
IPLV.IP|54/445|≥4.640|≥3.680|≥2.680|NA|≥8.330|≥6.410|≥4.CPC § 1.8.7 Medium relevance — show source text
|Over 750,
add 1 fix-
ture for
each addi-
tional 500
persons.|Over 750,
add 1 fix-
ture for
each addi-
tional 500
persons.|N otes: 1 The figures shown are based upon one fixture being the minimum required for the number of persons indicated or any fraction thereof. 2 A restaurant is defined as a business that sells food to be consumed on the premises. a. The number of occupants for a drive-in restaurant shall be considered as equal to the number of parking stalls. b. Hand-washing facilities shall be available in the kitchen for employees. 3 The total number of required water closets for females shall be not less than the total number of required water closets and urinals for males. [BSC] This requirement shall not apply when single occupancy toilet facilities are provided for each sex in an A or E occupancy with an occupant load of less than 50. Either
a. The required urinal shall be permitted to be omitted or b. If installed, the urinal shall not require a second water closet to be provided for the female. 4 For each urinal added in excess of the minimum required, one water closet shall be permitted to be deducted. The number of water closets shall not be reduced to less than two-thirds of the minimum requirement. 5 Metering or self-closing faucets shall be installed on lavatories intended to serve the transient public. 6 Service sinks shall not be required for non-residential occupancies with an occupant load of 15 or less. 7 For business and mercantile occupancies, one common service sink shall be permitted when accessible to all businesses and mercantile within 300 feet (91 440 mm) and within the same story. 8 [BSC, DSA-AC, DSA-SS, HCD 1 & HCD 2, OSHPD 1, 2, 3, 4 & 5] In accordance with Sections 1.8.7 and 301.3, the Authority Having Jurisdiction may approve alternative design criteria when determining the minimum number of plumbing fixtures.
74 2025 CALIFORNIA PLUMBING CODE
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
PLUMBING FIXTURES AND FIXTURE FITTINGS
TABLE 4-1 OCCUPANT LOAD FACTOR: [BSC & DSA-SS] Col2 **FUNCTION OF SPACE* **** OCCUPANT
LOAD FACTOR
(square feet)Assembly_ - without fixed seats_
Auditorium, convention and dance hall, lodge, stage, indoor sport/spectator event, worship, arcade, gaming
(standing space)11 Waiting, terminal (portable seating space) 15 Conference, dining/drinking, lounge (portable seating/table space) 30 Gallery, museum, exhibit (standing space) 30 Assembly_ – with fixed seats_ See CBC 1004.6
Use 50% of the fixed
seating valueBusiness_ (office, sales/soliciting, administration, food processing, courtroom, ambulatory clinic)_ 150
_See CBC 1004.CPC § 2.0 Medium relevance — show source text
0|2.0|2.0| |4|Clothes Washer|1|5.5|3.5|3.5| |5|Combination Bath/Shower|1|5.5|5.5|5.5| |6|Dishwasher|1|0.5|1.3|1.3| |7|Kitchen Faucet|1|2.0|2.2|2.2| |8|Laundry Faucet|0|2.0|2.0|2.0| |9|Lavatory Faucet|1|2.0|1.5|1.5| |10|Shower, per head|0|4.5|2.0|2.0| |11|Water Closet, 1.28 GPF Gravity Tank|1|1.0|3.0|3.0| |12|Other Fixture 1|0|0.0|0.0|6.0| |13|Other Fixture 2|0|0.0|0.0|6.0| |14|Other Fixture 3|0|0.0|0.0|6.0| |Total Number of Fixtures|Total Number of Fixtures|6||RESET|RUN WATER DEMAND
CALCULATOR| |99th Percentile Demand Flow =|99th Percentile Demand Flow =|8.5 GPM||||For SI units: 1 gallon per minute = 0.66 L/s, 1 gallon = 3.785 L
FIGURE 2 WATER DEMAND CALCULATOR FOR INDOOR USE AT HOME WITH SIX EFFICIENT FIXTURES (EXAMPLE 1)
Solution: Step 2 of 2 – Determine the Pipe Size of the Building Supply.
Chart A 105.1(1) for copper piping systems (from Appendix A of the UPC, shown in Figure 3) is used to determine the pipe size, based on given friction loss, given maximum allowable pipe velocity, given pipe material and the demand load computed in Step 1. In Figure 3, the intersection of the given friction loss (15 psi) (103 kPa) and the maximum allowable pipe velocity (10 ft/s) (3.05 m/s) is labeled point A. The vertical line that descends from point A to the base of the chart
intersects four nominal sizes for L-copper pipe. These intersection points are labeled B, C, D, E and correspond to pipe sizes of 1 inch (25 mm), [3] / 4 inch (20 mm), [1] / 2 inch (15 mm) and [3] / 8 inch (10 mm), respectively. A horizontal line from points B, C, D, E to the right-hand side of the chart gives maximum flow rates of 24 gpm (1.5 L/s), 12 gpm (0.757 L/s), 4.5 gpm (0.28 L/s), and 2.3 gpm (0.145 L/s), respectively. These results are summarized in Table 1 which shows that a [3] / 4 inch (20 mm) type L copper line is the minimum size that can convey the peak water demand of 8.5 gpm (0.54 L/s).
TABLE 1
PIPE SIZE OPTIONS FOR BUILDING SUPPLY
Frequently asked questions
Do I always assume a 50/50 male/female split?
Yes — the code’s default is 50% male / 50% female for calculating the minimum number of fixtures unless you submit reliable occupant‑distribution data that justify a different split. § 422.1.1.
If I provide all‑gender toilet rooms, how are they counted?
All‑gender fixtures are counted by calculating the aggregate number using the 50/50 split (or your justified split) and applying Table 422.1; the aggregate is the minimum required. § 422.1.1.
Can I replace urinals with water closets?
Yes. The code permits substituting a water closet for each urinal so long as the total number of fixtures complies with Table 422.1. § 422.1.1.
What if my space has a very small occupant load?
There are explicit exceptions for very small occupant loads (for example, one single‑occupant toilet serving both sexes is allowed for total loads of 10 or less; business/mercantile up to 50). Check the exceptions under § 422.0 and the adoption matrix for agency‑specific adoption.
Where do I find the exact number for my occupancy type?
Use Table 422.1 (the row that matches your occupancy classification) after you have determined the building occupant load by the California Building Code (or Table 4‑1). § 422.1 and Table 422.1 contain the precise figures.
More in California Plumbing Code
- Administration
- Definitions
- General Regulations
- Plumbing Fixtures and Fixture Fittings
- Water Heaters
- Water Supply and Distribution
- Sanitary Drainage (Drain, Waste, and Vent)
- Indirect Wastes
- Vents
- Traps and Interceptors
- Storm Drainage
- Fuel Gas Piping
- Health Care Facilities — Medical Gas and Medical Vacuum Systems
- Alternate Water Sources and Nonpotable Rainwater Catchment Systems
Ask about the CPC
Get cited, plain-English answers on the California Plumbing Code for your project — any code section, any scenario.
Start Free Trial