How Many Porta Potties You Need in Brooklyn
Enter the guest count and hours, or the number of workers, and the calculator applies the published event chart or the OSHA table, rounding up.
How many porta potties do you need for 100 guests?
The industry chart doesn't go that low. The Portable Sanitation Association International (PSAI) event chart starts at 500 guests, where it lists 2 units for a 1-hour event and 4 for 2 hours. For 100 guests, treat those figures as a ceiling, have at least one unit (plus an accessible unit if the public is invited), and settle the exact count with the rental company.
Brooklyn Porta Johns built this porta potty calculator for event organizers and site supers booking units in Brooklyn and the nearby parts of Queens, Manhattan and the Bronx. It runs the PSAI chart for events and OSHA's construction table for crews, and both modes round up, never down.
The chart has seven crowd rows. If your crowd falls between two, reading the larger row keeps you on the side of shorter lines. An event of 1,200 people uses the 2,000 row.
Porta potty calculator for events and jobsites
Your count
Enter your numbers and press Calculate.
The PSAI event chart, hour by hour
PSAI publishes this chart in its public brochure, based on a University of Missouri-St. Louis study. Its figures assume nobody pumps the units during the event and a crowd that's roughly half men, half women.
If alcohol is served, PSAI advises adding 10 to 20 percent. The calculator shows both ends of that range, rounded up to whole units.
Standard units only. Accessible units and handwashing stations are sized on top of these figures.
| Crowd | 1 hr | 2 hr | 3 hr | 4 hr | 5 hr | 6 hr | 7 hr | 8 hr |
|---|---|---|---|---|---|---|---|---|
| 500 | 2 | 4 | 4 | 5 | 6 | 7 | 9 | 9 |
| 1,000 | 4 | 6 | 8 | 8 | 9 | 9 | 11 | 12 |
| 2,000 | 5 | 6 | 9 | 12 | 14 | 16 | 18 | 20 |
| 3,000 | 6 | 9 | 12 | 16 | 20 | 24 | 26 | 30 |
| 4,000 | 8 | 13 | 16 | 22 | 25 | 30 | 35 | 40 |
| 5,000 | 12 | 15 | 20 | 25 | 31 | 38 | 44 | 50 |
| 10,000 | 15 | 25 | 38 | 50 | 63 | 75 | 88 | 100 |
Where the chart stops working
The chart answers the common case: a crowd of hundreds or thousands for an afternoon or an evening. Outside that box, you plan with the rental company instead.
Fewer than 500 guests
The first row is an upper bound for you. A backyard party or a small block party still needs at least one unit, and a public event needs an accessible one.
Longer than 8 hours
Past 8 hours the units need emptying, so the count depends on service visits during the event. See how often porta potties are serviced.
More than 10,000 people
The chart ends at 10,000. Crowds larger than that are planned around layout, clusters and servicing, not a single number.
5,000 people for 24 hours or more
An event this size and length can count as a mass gathering under New York State rules, which set their own ratio of 100 people per toilet seat. The New York portable toilet regulations page covers the permit.
How many porta potties per worker OSHA requires
OSHA 29 CFR 1926.51 Table D-1 sets the floor: one toilet for up to 20 employees, then one seat and one urinal per 40, and per 50 once the crew reaches 200. Every figure rounds up.
The table counts seats and urinals, not units. Ask whether the units on the quote include a urinal; if they don't, you may need extra units to cover the urinal count. Mobile crews and upper-floor work have their own rules, set out in full on the OSHA section of the regulations guide.
- 20 workers
- 1 toilet
- 41 workers
- 2 seats and 2 urinals
- 150 workers
- 4 seats and 4 urinals
- 240 workers
- 5 seats and 5 urinals
Accessible units and sinks are counted separately
Neither the PSAI chart nor the OSHA table tells you how many accessible units to order. For a public event, the ADA standards require a share of each cluster of portable toilets to be accessible; the ADA porta potty requirements guide works through the percentage.
Handwashing is its own count too. Food vendors, crews working with paints or chemicals, and large gatherings each bring a separate rule, covered in the handwashing station requirements guide.
Sizing questions
Does a crowd that is mostly women need more units than the chart shows?
Plan above the chart. It assumes an even mix of men and women, and PSAI lists a female-heavy crowd among the factors that push the count up, along with heat, food and drink. The event porta potty rental page covers those factors for Brooklyn events.
How many porta potties for a wedding of 150 guests?
A 150-guest wedding sits below the first row of the PSAI chart, so the chart gives an upper bound, not an answer. Weddings often use a restroom trailer instead of separate units. Give the rental company the guest count, the hours and whether there's a bar, and compare their count to the chart's 500-guest row.
Is the jobsite count based on total workers or workers per shift?
OSHA's table counts employees. In practice, size the order for the busiest stretch of the job, when the most trades overlap, because that is when a short count shows. Add a unit when the crew grows rather than waiting for complaints.
Bring the number to the call
Say the count the calculator gave you, the hours and whether there's a bar. The rental company can confirm it or adjust for your crowd before anything is booked.