Sizing guide
How Many Porta Potties Do I Need?
Enter your guest count and hours, or read the chart. Every number shows its math, and the worked example walks through each step.
Live answer 7 AM–6 PM. Quote requests answered within 1 business hour.
Porta potty calculator
The calculator uses 1 unit per 50 guests for a 4-hour event, scaled for longer events, plus 1 extra unit for every 4 when alcohol is served. For crews, it shows the OSHA minimum and our weekly-cleaning recommendation of 1 unit per 10 workers.
How many porta potties do I need per guest?
You need 1 porta potty for every 50 guests at an event that lasts up to 4 hours. For longer events, multiply by the hours divided by 4 and round up. A 200-guest, 8-hour event needs 8 units. Alcohol, a mostly female crowd or heavy drinking water at summer events push the count higher.
| Guests | 1–4 hours | 5 hours | 6 hours | 8 hours | 10 hours |
|---|---|---|---|---|---|
| 25 | 1 | 1 | 1 | 1 | 2 |
| 50 | 1 | 2 | 2 | 2 | 3 |
| 100 | 2 | 3 | 3 | 4 | 5 |
| 150 | 3 | 4 | 5 | 6 | 8 |
| 200 | 4 | 5 | 6 | 8 | 10 |
| 300 | 6 | 8 | 9 | 12 | 15 |
| 500 | 10 | 13 | 15 | 20 | 25 |
| 1,000 | 20 | 25 | 30 | 40 | 50 |
Method: guests ÷ 50, multiplied by hours ÷ 4 when the event runs over 4 hours, rounded up to a whole unit. This follows the common industry rule of 1 unit per 50 people per 4 hours, used by the Portable Sanitation Association International.
How do I adjust for alcohol, food and accessibility?
Adjust the base count in whole-unit steps. Add 1 unit for every 4 when beer, wine or liquor is served. Add 1 hand-washing station for every 4 units when food is served. Make at least 5 percent of units in each cluster wheelchair-accessible for public events, and never fewer than one.
Worked example: 150 guests, 5 hours, beer, public
- 150 guests ÷ 50 = 3 units for 4 hours.
- The event runs 5 hours: 3 × 5 ÷ 4 = 3.75, so round up to 4 units.
- Beer is served: add 1 unit for every 4, so 4 + 1 = 5 units.
- It is open to the public: 5% of 5 is 0.25, so the minimum of 1 applies. Make 1 of the 5 units wheelchair-accessible.
- Food is served: 5 ÷ 4 = 1.25, which rounds to 1 hand-washing station. Two stations are better if there is a food line.
Order: 4 standard units, 1 ADA unit, 1–2 hand-washing stations.
Accessibility rule: 2010 ADA Standards, section 213.2.
How many porta potties does a work crew need?
A work crew of 20 or fewer needs at least 1 toilet under OSHA 29 CFR 1926.51. Larger crews need 1 toilet seat and 1 urinal per 40 workers, or per 50 workers at 200 and up. With weekly cleaning, 1 unit serves about 10 workers on a 40-hour week before the tank gets too full.
A crew of 25 meets the legal minimum with 1 seat and 1 urinal. That crew still needs about 3 units to last a full week between cleanings. The full rule, plus the farm-crew rule, is in the OSHA requirements guide. Ready to book? Job-site rentals or event rentals.
Sizing questions
Do men and women need separate units?
Separate units are not required, but at events over 100 guests, labeling one unit for women and one for men shortens lines. Women's restroom visits take longer, so many planners add 1 extra unit marked for women at large events.
Does the house bathroom count?
One indoor bathroom counts as about 1 unit for a party of up to 50 guests. Most hosts still rent 1 porta potty to keep guests out of the house and spare a small septic tank.
How many units for a 3-day festival?
A 3-day festival needs units sized for its busiest day plus a cleaning visit each night. A festival with 1,000 guests a day over 8 hours needs about 40 units, cleaned nightly. With alcohol, plan on 50.
How do I size a restroom trailer?
A 2-stall restroom trailer handles about 100 guests over a 5-hour event, and a 3-stall handles about 150. Add flushing units if the guest list or the bar runs longer.
Get your itemized quote
The fastest way to get a sizing quote is to call (402) 313-6717 and talk to the person who schedules the trucks. If you prefer to type, send the six details in the form. We reply within one business hour with a single price that lists the unit, delivery, pickup, cleaning and tax.
Got your number?
Call and we will double-check it against your site and dates.