How many porta potties do I need?
One unit per 50 guests for a 4-hour event is the starting point. Use the calculator for your exact numbers.
- Weekly cleaning included
- Itemized quotes
- Event units kept separate
By Roy, owner of ApexFlow Restroom Co. Reviewed 2026-10-27.
2 units.
4 units; 5 with alcohol.
4 units + 1 accessible.
1 unit, weekly service.
Cal/OSHA minimum 2; we suggest 3.
Porta potty calculator
Enter your guest count, event length and whether alcohol or food is served. The calculator applies 1 unit per 50 guests for 4 hours, then adds whole units for time and alcohol, and shows the accessible units and hand-washing stations to add.
Assumptions: events use 1 unit per 50 guests for up to 4 hours, plus 1 unit per 100 guests for each extra 3 hours, plus 1 unit per 100 guests when alcohol is served. Job sites use 1 unit per 10 workers with weekly service (Cal/OSHA's legal minimum is 1 per 20). Public clusters get at least 1 wheelchair-accessible unit (5% rule). Food events get 1 hand-washing station per 4 toilets.
How many porta potties for 100 guests?
A 100-guest event needs 2 porta potties for up to 4 hours. A 100-guest event that runs 5 to 7 hours needs 3 units. Add 1 more unit if alcohol is served. Add 1 hand-washing station if food is served, and 1 wheelchair-accessible unit for a public event.
| Guests | 1 to 4 hours | 5 to 7 hours | 8 to 10 hours | Add for alcohol |
|---|---|---|---|---|
| 50 | 1 | 2 | 3 | +1 |
| 100 | 2 | 3 | 4 | +1 |
| 150 | 3 | 5 | 7 | +2 |
| 200 | 4 | 6 | 8 | +2 |
| 300 | 6 | 9 | 12 | +3 |
| 500 | 10 | 15 | 20 | +5 |
| 1,000 | 20 | 30 | 40 | +10 |
Worked example: a 150-guest wedding for 6 hours with a bar. Start with 3 units for 4 hours. Add 2 units for the extra hours (1 per 100 guests per 3 hours, rounded up). Add 2 units for alcohol. Total: 7 units, or a 3-stall trailer plus 2 units. Make 1 of them wheelchair-accessible.
How many porta potties does a construction crew need?
A construction crew needs at least 1 toilet per 20 workers of each sex under Cal/OSHA Title 8 section 1526. With weekly service, plan 1 standard unit per 10 workers so the tank does not fill before the driver returns. A crew of 25 needs 2 by law; we suggest 3.
See construction porta potty rental for the full crew table and the legal text.
When should I add more units than the chart shows?
Add more units than the chart shows when most guests arrive at once, when the event has a single break such as a race start or halftime, when it is over 95°F, or when kids and older guests attend. Lines form at breaks, not across the whole event.
- Races and tournaments: add 1 unit per 100 people near the start line.
- Women-heavy events, such as showers: add 1 unit per 100 guests.
- Events over 1,000: ask for a site plan with clusters at each end.
Sizing questions
How many porta potties do I need for 50 people?
Fifty people need 1 porta potty for an event up to 4 hours. For 5 hours or more, or with alcohol, rent 2. A deluxe unit with a sink works well for a 50-person family party.
How many porta potties for 500 people?
Five hundred people need 10 porta potties for a 4-hour event, plus at least 1 wheelchair-accessible unit per cluster and 2 to 3 hand-washing stations. A full-day event needs about 20 units.
Does one restroom trailer stall equal one porta potty?
One trailer stall handles a bit more than one porta potty because it has a larger tank and is easier to use quickly. Plan about 50 to 75 guests per stall for a 5-hour event.
Can I use one unit for both men and women?
One single-user unit works for everyone at a private party. Many hosts with 60 to 100 guests rent two and label one for women. For job sites, Cal/OSHA counts toilets by sex, and small crews under five may share one all-gender unit.
Keep planning
Get an itemized quote
An itemized porta potty quote lists the unit, delivery, pickup, the service schedule, any rush fee and tax, so the number you approve is the number you pay. Send six quick fields below, or call for the fastest answer and a same-day slot.
- Delivery and pickup on the quote, not added later
- Weekly service listed for rentals of a week or longer
- Any rush or fuel charge shown before you pay
Answered live Monday to Saturday, 7 am to 7 pm. Same-day orders are booked by phone.