Porta potty calculator for events
The PSAI special-event chart
The Portable Sanitation Association International (PSAI) publishes this chart in its public brochure on renting portable restrooms. It gives the number of units by average crowd size and the average number of hours people stay. PSAI notes it assumes no pumping service during the event and an even mix of men and women.
| Crowd | 1 hr | 2 hrs | 3 hrs | 4 hrs | 5 hrs | 6 hrs | 7 hrs | 8 hrs |
|---|---|---|---|---|---|---|---|---|
| 500 | 2 | 4 | 4 | 5 | 6 | 7 | 9 | 9 |
| 1,000 | 4 | 6 | 8 | 8 | 9 | 9 | 11 | 12 |
| 2,000 | 5 | 6 | 9 | 12 | 14 | 16 | 18 | 20 |
| 3,000 | 6 | 9 | 12 | 16 | 20 | 24 | 26 | 30 |
| 4,000 | 8 | 13 | 16 | 22 | 25 | 30 | 35 | 40 |
| 5,000 | 12 | 15 | 20 | 25 | 31 | 38 | 44 | 50 |
| 10,000 | 15 | 25 | 38 | 50 | 63 | 75 | 88 | 100 |
Round your crowd up to the next row. The chart's source line credits an independent study by the Center of Business and Industrial Studies at the University of Missouri-St. Louis.
Adjust for alcohol, long days and layout
- Alcohol: PSAI says to add 10–20% more units if alcohol is served.
- Longer than 8 hours: the chart stops at 8 hours. For all-day or multi-day events, plan servicing (pumping and restocking) during the event; call and we will plan it with the provider.
- Everyone on site counts: include staff, vendors, performers and volunteers, not just guests.
- Layout: big sites need restrooms in several places so no one walks far, which can mean more units than the chart shows.
How many ADA-accessible units?
The U.S. Access Board's guide to the ADA Standards says that where portable single-user toilet units are provided, including at temporary events, at least 5% of the units in each cluster must be accessible and marked with the International Symbol of Accessibility. The guide notes rounding up is required when a percentage gives a fraction (ADA Standards §104.2), so a cluster of 1 to 20 units needs at least one accessible unit, 21 to 40 needs two, and so on. Units on construction sites used only by construction personnel are exempt. See ADA porta potty rental.
How many porta potties for a construction site?
OSHA 29 CFR 1926.51(c)(1) sets the minimum number of toilet facilities on construction jobsites:
| Number of employees | Minimum toilet facilities |
|---|---|
| 20 or fewer | 1 toilet |
| 20 or more | 1 toilet seat and 1 urinal per 40 workers |
| 200 or more | 1 toilet seat and 1 urinal per 50 workers |
For example, a crew of 60 needs at least 2 toilet seats and 2 urinals under the 1-per-40 rule. More on construction porta potty rental.
Hand-washing stations
Standard porta potties usually have sanitizer but no sink. Add hand-washing stations beside restroom rows and near any food or animals.
