How Many Porta Potties Do I Need?
Use the calculator, the event chart and the OSHA crew table to get the right count for a party, wedding, festival or job site, with every adjustment shown as whole numbers.
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The rules in 25 words
Straight answers. No runaround.
- Party?
- 1 unit per 50 guests for 4 hours.
- Alcohol?
- Add 1 unit for every 4.
- Food?
- Add 1 hand-wash station per 4 units.
- ADA?
- At least 1 per cluster.
- Crew?
- OSHA: 1 toilet up to 20 workers.
Porta potty calculator
Enter your guest count and hours, or your crew size and weekly hours. The calculator uses 1 standard unit per 200 guest-hours for events, adds whole units for alcohol and mostly-women crowds, and uses OSHA Table D-1 plus a 1-per-10 recommendation for crews.
- Includes at least 1 ADA unit for guests who use a wheelchair.
How many porta potties do I need for an event?
An event needs 1 standard porta potty for every 200 guest-hours. Multiply guests by hours and divide by 200, then round up: 150 guests for 5 hours is 750 guest-hours, or 4 units. Add 1 unit if alcohol is served, which makes 5 units for a 150-guest wedding with a bar.
| Guests | 2 hours | 4 hours | 6 hours | 8 hours |
|---|---|---|---|---|
| 25 | 1 | 1 | 1 | 1 |
| 50 | 1 | 1 | 2 | 2 |
| 100 | 1 | 2 | 3 | 4 |
| 150 | 2 | 3 | 5 | 6 |
| 200 | 2 | 4 | 6 | 8 |
| 300 | 3 | 6 | 9 | 12 |
| 500 | 5 | 10 | 15 | 20 |
| 1,000 | 10 | 20 | 30 | 40 |
Adjustments, in whole units
- Alcohol: add 1 unit for every 4 in the chart (at least 1).
- Mostly women guests: add 1 unit for every 5 in the chart (at least 1).
- Food served: add 1 two-basin hand-wash station for every 4 units (at least 1).
- Accessibility: at least 5% of units in each cluster, never fewer than 1, wheelchair-accessible (2010 ADA Standards, section 213.2).
Where the method comes from: a standard unit holds about 200 uses before it needs pumping. Our planning rule assumes about one restroom visit per guest per hour, which gives 1 unit per 200 guest-hours with room to spare. Adjustments are our recommendation, not a legal requirement.
How many porta potties does a construction crew need?
A construction crew of 20 or fewer workers needs at least 1 toilet under OSHA 29 CFR 1926.51 Table D-1. Above 20 workers, OSHA requires 1 seat and 1 urinal per 40 workers. We recommend 1 standard unit per 10 workers on a 40-hour week, with weekly service, and more service for longer weeks.
| Number of workers | OSHA minimum (Table D-1) | Our recommendation (40-hr week, weekly service) |
|---|---|---|
| 1–10 | 1 toilet | 1 standard unit |
| 11–20 | 1 toilet | 2 standard units |
| 21–40 | 1 seat + 1 urinal per 40 workers | 3–4 units, with urinals |
| 41–80 | 2 seats + 2 urinals | 5–8 units + 2 hand-wash stations |
| 81–200 | 1 seat + 1 urinal per 40 workers | 1 unit per 10 workers, service twice a week |
| 200+ | 1 seat + 1 urinal per 50 workers | Custom plan with multiple service days |
The rule: OSHA 29 CFR 1926.51. Legal minimums can be lower than what keeps a crew comfortable; the recommendation column reflects weekly service on a 40-hour week.
Worked example: 32 workers, 50-hour week. OSHA minimum: 1 seat + 1 urinal. Recommendation: 32 ÷ 10 = 4 units (round up), and because the week is 50 hours, add a second weekly service.
What about farm crews?
Farms with 11 or more hand laborers in the field need 1 toilet and 1 hand-washing facility per 20 workers, within a quarter-mile walk, under OSHA 29 CFR 1928.110. A 35-person harvest crew needs 2 toilets and 2 hand-wash facilities near the block being picked.
The rule: OSHA 29 CFR 1928.110. See our farm and orchard rentals for placement tips.
Next: party and event rentals · wedding restroom setups · festival layouts · construction site units · what your count will cost.
Sizing questions
Quick answers to sizing questions. The dispatcher double-checks your count when you book. Open a question for the full answer. If yours is not here, call (540) 575-8909 and dispatch answers it on the spot, Monday through Saturday.
QHow many porta potties do I need for a party?
Plan on 1 standard unit per 50 guests for a 4-hour party. For 100 guests over 4 hours that is 2 units. Add 1 unit if alcohol is served, and include at least 1 ADA unit if any guest uses a wheelchair.
QHow many restrooms for a wedding of 150?
A 150-guest, 5-hour wedding with a bar needs about 5 standard units, or one 3- to 4-stall restroom trailer plus 1 ADA unit. Add a hand-wash station near the food.
QHow many porta potties does my crew need?
OSHA requires 1 toilet for 20 or fewer workers, and 1 seat plus 1 urinal per 40 workers above 20. We recommend 1 standard unit per 10 workers on a 40-hour week with weekly service.
QWill it overflow during my party?
A standard unit handles about 200 uses before it needs pumping. If your headcount is above the guide for the hours you plan, add a unit or a mid-event service. Our sizing guide shows the right count.
QDo you have hand-washing stations?
Stand-alone hand-wash stations come with fresh water, foot pumps, soap and paper towels. Two people can use one at the same time. They are a good add-on wherever food is served.
QDo you have handicap-accessible porta potties?
Wheelchair-accessible units are available with a ground-level floor, a wide door, grab bars and room for a 60-inch turning circle. Ask early for weekend events, since ADA units book first.
Get an itemized quote
Fastest answer: call. Prefer text? Send this form with your ZIP, dates and headcount, and we reply by phone or text within business hours, usually inside an hour. Your quote lists the unit, delivery, pickup, the cleaning schedule and tax on separate lines, so the price you approve is the price you pay.
- Unit + delivery + pickup on one line
- Service schedule spelled out
- Tax shown before you pay
Mon–Sat, 7 a.m.–7 p.m.. Same-day delivery is available on many weekdays when you call early.