Toilet Fixture Calculator
Calculate the number of WCs, urinals and wash basins required for a given occupancy.
Assumptions used in this calculation
- Simplified ratios: A general planning estimate, actual code requirements vary by jurisdiction and occupancy type.
About this calculator
Plumbing codes set minimum fixture counts based on how many people a building serves, and undersizing restroom facilities relative to occupancy is a common design oversight that creates real queuing problems once a building is occupied, not just a compliance issue at plan review. This calculator divides your building's total occupant count by an occupants-per-fixture ratio to estimate minimum water closets, and separately applies an occupants-per-basin ratio to estimate minimum wash basins, rounding each up to a whole fixture count since fixtures aren't divisible. Enter total occupants along with your applicable occupants-per-WC and occupants-per-basin ratios, and get both minimum fixture counts at once instead of calculating each fixture type separately by hand. These are general planning ratios, actual code requirements vary meaningfully by jurisdiction and occupancy type, and some codes further split requirements by gender or require separate accessible fixtures, so confirm the specific plumbing code applicable to your building before finalizing a restroom layout.
Worked example
100 occupants, 1 fixture per 25 people
Result: 4 WCs (or split with urinals), 3 wash basins
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