Free calculator · events and job sites
How Many Porta Potties Do I Need?
Plan one porta potty per 50 guests for a four-hour event, about 25% more when alcohol is served, extra for events over four hours, at least one ADA unit and a hand-washing station for every four to five units. For job sites, OSHA requires one toilet for up to 20 workers and one per 40 beyond that.
Porta potty calculator
Event porta potty chart
| Guests | Up to 4 hrs | 4–8 hrs | 4–8 hrs + alcohol | Hand-wash |
|---|---|---|---|---|
| 50 | 1 | 2 | 2 | 1 |
| 100 | 2 | 3 | 4 | 1 |
| 200 | 4 | 6 | 8 | 2 |
| 300 | 6 | 9 | 12 | 3 |
| 500 | 10 | 15 | 19 | 4 |
| 1,000 | 20 | 30 | 38 | 8 |
Construction site chart (OSHA 1926.51)
| Workers | OSHA minimum | Recommended, weekly service |
|---|---|---|
| 1–10 | 1 | 1 |
| 11–20 | 1 | 2 |
| 40 | 1 seat + 1 urinal | 4 |
| 80 | 2 seats + 2 urinals | 8 |
| 200 | 4 seats + 4 urinals | 20, or fewer with twice-weekly service |
Five things that change the count
- Alcohol and drinks raise restroom visits by about a quarter.
- Long events over four hours need more units or a mid-event service.
- Mostly women or children means longer visits, so add a unit.
- Big grounds need two clusters so the walk stays short.
- Public events need ADA units equal to about 5% of the total.
Sizing questions
How many porta potties do I need for 200 guests?
For 200 guests over four hours, plan four units. For an evening event with alcohol, plan five to six, including one ADA unit, plus two hand-washing stations.
How many porta potties for 50 people?
One unit handles 50 people for about four hours. Add a second unit if the event runs past six hours, alcohol is served or the group is mostly adults over a full day.
How many porta potties does OSHA require?
OSHA 29 CFR 1926.51 requires one toilet for 20 or fewer workers, one toilet seat and one urinal per 40 workers for 20 to 199 workers, and one seat and one urinal per 50 workers for 200 or more.
How many uses does a porta potty hold?
A standard 60-gallon unit handles roughly 200 to 250 uses before it needs service. That is why one unit covers about 10 workers for a week or about 50 guests for an afternoon.
Do I need a hand-washing station?
Plan one hand-washing station for every four to five units and one at every food area. Food events and farm or animal events should always include real sinks.