How many restrooms
does your site need?

Event planning assumptions

The one-per-50 baseline is an initial planning example for a private gathering. It does not establish a universal capacity, a legal requirement, or sufficient facilities for every event. Longer duration, drinks, food, queue tolerance, and separate activity areas can change the recommendation.

The planner does not automatically subtract indoor restrooms. Their actual availability, location, and suitability need confirmation. Accessible units and handwashing must also be included in the final plan.

Construction minimums and practical servicing

OSHA 29 CFR 1926.51(c)(1), Table D-1 states the following construction requirements. The wording has overlapping thresholds at 20 workers; review the standard in context rather than treating this table as a complete compliance calculator.

Separately, OSHA’s sanitation interpretation discusses a servicing guide of a weekly visit for a toilet used by up to 10 people. Our one-per-10 construction count is a conservative service-planning starting point, not the statutory employee-count formula. It assumes a typical 40-hour week and requires review for shifts or heavier use.

A worked construction example

For 25 workers, 25 ÷ 10 = 2.5; rounding up gives 3 units for the initial service discussion. The applicable legal minimum and the operational plan are separate checks. If those workers cover multiple shifts or longer hours, ask for a revised service and equipment plan.

Accessibility is a layout decision too

Tell us if facilities must meet ADA requirements and how many restroom clusters your site has. The ADA scoping provisions in §213.2 and accessible-route requirements need to be reviewed for the actual site. The calculator does not determine legal accessibility quantities.

See construction rentals, event restrooms, and accessible equipment for the next planning step.