Sizing guide · calculator
How Many Porta Potties Do I Need?
Enter your guest count and hours. The calculator shows the units, the accessible units and the handwashing stations, with the math shown.
- Delivery areaSame counts apply anywhere we deliver. See our service areas.
- ArrivalBook 1 to 2 weeks ahead for events; same day by 12 pm for job sites.
- Which unit1 standard unit per 50 guests for 4 hours. +1 per 4 units with alcohol.
- CleaningEvent units are not serviced mid-event, so the chart assumes one fill.
- Full costStandard units from $165 per event. See the cost guide.
Written by Craig, owner of Craig Rental Works. Updated .
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How many porta potties do I need per guest?
Plan 1 standard porta potty for every 50 guests at an event of up to 4 hours. A 100-guest, 4-hour party needs 2 units. A 200-guest, 6-hour wedding needs 3 units, plus 1 more if alcohol is served. Every event cluster needs at least 1 wheelchair-accessible unit.
Big crowds share units better, so above 200 guests use the chart, not the 1-per-50 rule. The chart below is the planning method Craig Rental Works uses on every call. It assumes a mixed crowd of adults and units that are not serviced during the event.
| Guests | Up to 2 hr | 4 hr | 6 hr | 8 hr | 10 hr |
|---|---|---|---|---|---|
| 25 | 1 | 1 | 1 | 1 | 2 |
| 50 | 1 | 1 | 2 | 2 | 2 |
| 100 | 1 | 2 | 2 | 3 | 3 |
| 150 | 2 | 2 | 3 | 3 | 4 |
| 200 | 2 | 3 | 3 | 4 | 5 |
| 250 | 3 | 3 | 4 | 5 | 6 |
| 300 | 3 | 4 | 5 | 6 | 7 |
| 400 | 4 | 5 | 6 | 7 | 8 |
| 500 | 4 | 6 | 7 | 8 | 9 |
| 750 | 6 | 8 | 10 | 11 | 12 |
| 1,000 | 8 | 10 | 12 | 14 | 16 |
How do I adjust the count for alcohol, hours and food?
Adjust the chart in whole units. If alcohol is served, add 1 unit for every 4 units the chart shows (at least 1). If the chart says 5 units and beer is served, book 6. Add 1 handwashing station for every 4 toilets, plus 1 near any food line.
Worked example: 150-guest wedding, 6 hours, open bar
- Find the chart row150 guests at 6 hours = 3 standard units.
- Add for alcohol3 ÷ 4 rounds up to 1. 3 + 1 = 4 units.
- Add accessible units5% of 4 rounds up to 1. Make 1 of the 4 wheelchair-accessible.
- Add handwashing4 toilets ÷ 4 = 1 station, plus 1 near the buffet = 2 stations.
Result: 3 standard units, 1 wheelchair-accessible unit and 2 handwashing stations. Or use one 2-stall restroom trailer plus 1 standard unit and 1 accessible unit.
How many porta potties does a construction site need?
A construction site needs 1 toilet for up to 20 workers under OSHA 29 CFR 1926.51, and 1 seat plus 1 urinal per 40 workers above 20. For weekly service, Craig Rental Works recommends 1 standard unit per 10 workers on a 40-hour week.
Farms follow a different rule: OSHA 1928.110 requires 1 toilet and 1 handwashing facility for every 20 field workers, within a quarter-mile walk. See the full OSHA table · OSHA 1926.51
Most first guesses are low for long events. 500 people over 9 hours needs about 9 units on the chart, not 3. If you are between two numbers, round up; a line at the porta potty is what guests remember.
How many porta potties FAQs
How many porta potties for 50 guests?
For 50 guests over 4 hours, 1 standard unit is enough. For 6 hours or more, rent 2.
How many porta potties for 100 guests?
For 100 guests over 4 hours, rent 2 standard units. Add 1 if alcohol is served.
How many porta potties for 200 guests?
For 200 guests over 4 hours, rent 3 standard units. For 6 hours with alcohol, rent 4 to 5.
How many porta potties for 500 people?
For 500 people over 6 hours, rent 7 standard units, plus 2 more with alcohol, 1 accessible unit per cluster and 2 to 3 handwashing stations.
Do women need more units than men?
Yes. Women take longer per visit. For women-heavy events like showers, add 1 unit to the chart count.
Does a restroom trailer replace porta potties?
A 2-stall trailer covers about 100 guests for 4 hours, roughly the same as 2 standard units, with more comfort.
Related guides
Book the right number of units
Call with your count; we double-check the math and hold your date.
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