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Plumbing Fixture Calculator

Minimum fixture counts per NSPC Table 7.21.1 additive bands. Supports mixed occupancies with all sub-types (A-1 through S-2). 50/50 gender split assumed per NSPC 7.21.2(c) unless adjusted. Urinal substitution applies the NSPC 7.21.5(a) cap (50% maximum for all occupancies).
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Occupancies
Settings
Apply 2/3 occupant load reduction
NSPC 7.21.2(b) — Where occupant load is based on egress requirements, plumbing load may be reduced to 2/3
Apply urinal substitution (male WC reduction)
NSPC 7.21.5(a) — Urinals may replace up to 50% of required male WCs in all occupancies. Cap applied per occupancy.

Required Fixtures

Fixture Male Female Total
This calculator provides preliminary estimates based on NSPC Table 7.21.1 additive fixture bands (2021 NJ edition). All occupancy sub-types (A-1 through S-2) are encoded with their specific band data. The 2/3 occupant-load reduction follows NSPC 7.21.2(b). Gender split defaults to 50/50 per NSPC 7.21.2(c). Urinal substitution follows NSPC 7.21.5(a): up to 50% of required male WCs may be replaced with urinals. Fractional values are summed across occupancies and rounded up per NSPC 7.21.10. I-2 patients (1 WC + 1 lav per patient room), R-2 apartments (1 WC + 1 lav per unit), and R-3/R-5 dwellings (1 WC + 1 lav per unit) require per-unit counts and are not calculated by occupant load — select those types for guidance. Verify all counts against the current NJ-adopted edition of the National Standard Plumbing Code. This tool does not replace professional code analysis. Green Stories LLC is a building design and consulting firm.