How many porta potties do I need for my event?
An event needs 1 porta potty for every 250 guest-hours, rounded up, with a minimum of 1. Multiply guests by event hours and divide by 250. A 100-guest party that runs 4 hours needs 2 porta potties. Add units for alcohol and add hand wash stations for food.
Event porta potty calculator
Enter guests and hours to see your estimate.
Assumptions: our planning rule (guests × hours ÷ 250, rounded up), +1 unit per 4 when alcohol is served, 1 hand wash station per 3 toilets with food, and at least 5% wheelchair-accessible units per cluster (2010 ADA Standards §213.2). This is a planning estimate, not a legal requirement.
This is our planning rule from years of Whittier events, not a law. Your venue, permit office or safety officer may ask for more. Need a unit fast? See same-day porta potty delivery.
How many porta potties for 50 to 500 guests?
The porta potty count for 50 to 500 guests ranges from 1 unit to 16 units, depending on how long the event runs. A 2-hour event for 50 guests needs 1 unit. An 8-hour event for 500 guests needs 16 units. Every number below uses guests × hours ÷ 250, rounded up.
| Guests | 2 hours | 4 hours | 6 hours | 8 hours |
|---|---|---|---|---|
| 50 guests | 1 | 1 | 2 | 2 |
| 100 guests | 1 | 2 | 3 | 4 |
| 150 guests | 2 | 3 | 4 | 5 |
| 200 guests | 2 | 4 | 5 | 7 |
| 300 guests | 3 | 5 | 8 | 10 |
| 500 guests | 4 | 8 | 12 | 16 |
Read across your guest row to your event length. These counts assume no alcohol. Add the alcohol adjustment below if you serve drinks. Then make sure at least 1 unit in each group is wheelchair-accessible.
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How many extra porta potties do I need when alcohol is served?
Alcohol adds 1 porta potty for every 4 units in the base count, rounded up. Guests who drink use the restroom more often. A 150-guest, 5-hour party starts at 3 units (150 × 5 ÷ 250 = 3). The bar adds 1, so the party needs 4 porta potties.
| Event | Base units | Alcohol add | Total toilets | Of those, wheelchair-accessible | Hand wash stations (food) |
|---|---|---|---|---|---|
| 100 guests, 4 hours | 2 | +1 | 3 | 1 | 1 |
| 150 guests, 5 hours | 3 | +1 | 4 | 1 | 2 |
| 200 guests, 6 hours | 5 | +2 | 7 | 1 | 3 |
| 300 guests, 8 hours | 10 | +3 | 13 | 1 | 5 |
| 500 guests, 6 hours | 12 | +3 | 15 | 1 | 5 |
Worked example: 150 guests × 5 hours = 750 guest-hours. 750 ÷ 250 = 3 units. Alcohol adds 3 ÷ 4 = 0.75, rounded up to 1. Total: 4 porta potties, with 1 wheelchair-accessible. With food, plan 2 hand wash stations: 1 per 3 toilets, rounded up.
How many hand wash stations do I need for an event?
Plan 1 hand wash station for every 3 toilets when food is served, with a minimum of 1. A standard porta potty has hand sanitizer only, not a sink. Each 2-station PolyJohn Bravo handles about 350 hand washes per fill, so 1 station covers most backyard parties.
Put the station between the restrooms and the food line. Guests see it on the way back. If space is tight, choose the standard unit with a built-in hand sink instead. Compare options on our hand wash station page.
How many wheelchair-accessible porta potties do I need?
The 2010 ADA Standards §213.2 say at least 5% of porta potties in each cluster, and no fewer than 1, must be accessible. A cluster of 1 to 20 units needs 1 accessible unit. A cluster of 21 to 40 units needs 2. Two separate clusters each need their own accessible unit.
| Units in a cluster | Minimum accessible units (5%, at least 1) |
|---|---|
| 1–20 | 1 |
| 21–40 | 2 |
| 41–60 | 3 |
| 61–80 | 4 |
Our wheelchair-accessible unit is the PolyJohn Comfort XL. It has a ground-level roll-in floor, a 32-inch door opening and handrails. It needs a 66-inch-wide path. Source: U.S. Access Board, 2010 ADA Standards. See our wheelchair-accessible porta potty page.
Check first: This is the rule as we understand it, not legal advice. Confirm accessibility needs with your venue or permit office.
What do real porta potty counts look like for events?
Four worked porta potty examples cover most events we plan: a 150-guest wedding with a bar needs 5 toilets, a 300-person festival over 6 hours needs 8 to 10, a 12-worker jobsite needs 1 to 2, and a half-marathon used 14 units: 12 standard plus 2 wheelchair-accessible.
150-guest wedding with a bar, 6 hours
150 × 6 ÷ 250 = 3.6, rounded up to 4. The bar adds 1. Total: 5 toilets, with 1 wheelchair-accessible. Dinner is served, so plan 2 hand wash stations. Many couples swap the standard units for deluxe flushing units or a trailer. See wedding restroom options.
300-person festival, 6 hours
300 × 6 ÷ 250 = 7.2, rounded up to 8 toilets. With a beer garden, add 2 for 10. With food vendors, plan 4 hand wash stations. Split into 2 clusters of 5, and each cluster needs 1 wheelchair-accessible unit. More planning help is on our festival porta potty page.
12-worker jobsite
Cal/OSHA §1526 requires 1 toilet per 20 workers. 12 ÷ 20 rounds up to 1 toilet per sex. With 12 people on 1 unit, we recommend 2 services a week, or 2 units with weekly service. Add 1 hand wash station.
Half-marathon
One race customer rented 14 units: 12 standard and 2 wheelchair-accessible. Runners use restrooms in a burst before the start, so we put most units near the start line. Every cluster should include a wheelchair-accessible unit.
How many porta potties does a construction site need?
A California construction site needs at least 1 toilet for every 20 workers, or fraction of 20, of each sex, under Cal/OSHA Title 8 §1526. Crews under 5 workers may share 1 single-user all-gender toilet. A 12-worker site needs 1 toilet minimum; we add a second weekly service.
Jobsite toilet calculator (Cal/OSHA)
Enter your crew size.
Based on Cal/OSHA Title 8 §1526: at least 1 toilet per 20 employees or fraction of 20, of each sex. Confirm requirements with your safety officer.
| Crew size | Cal/OSHA §1526 minimum | Federal OSHA Table D-1 | Our service recommendation |
|---|---|---|---|
| 4 workers | 1 per sex (a single-user all-gender unit is OK under 5 workers) | 1 toilet | Weekly |
| 10 workers | 1 per sex | 1 toilet | Weekly |
| 20 workers | 1 per sex | 1 toilet | 2× per week (or add units) |
| 35 workers | 2 per sex | 1 seat + 1 urinal | 2× per week (or add units) |
| 60 workers | 3 per sex | 2 seats + 2 urinals | 2× per week (or add units) |
| 100 workers | 5 per sex | 3 seats + 3 urinals | 2× per week (or add units) |
| 150 workers | 8 per sex | 4 seats + 4 urinals | 2× per week (or add units) |
Federal OSHA 29 CFR 1926.51(c) Table D-1 says: 20 or fewer workers, 1 toilet; 20 or more, 1 seat and 1 urinal per 40 workers; 200 or more, 1 seat and 1 urinal per 50. Each PolyJohn PJN3 has 1 seat and 1 urinal. Handwashing is covered by 1926.51(f). California sites follow Cal/OSHA, which is stricter.
Sources: Cal/OSHA Title 8 §1526 and OSHA 29 CFR 1926.51. Full jobsite advice is on our construction site toilet page.
Minimum vs. recommendation: The legal minimum is a floor. Our recommendation adds service when more than about 10 workers share 1 unit on a 40-hour week. Confirm requirements with your safety officer.
How many toilets does a farm crew need in California?
A California farm crew needs 1 toilet and 1 handwashing facility for every 20 employees under Cal/OSHA Title 8 §3457. Both must sit within a 1/4-mile walk or 5 minutes of where people work. A 45-person harvest crew needs 3 toilets and 3 hand wash stations.
| Field crew | Toilets | Handwashing facilities | Distance rule |
|---|---|---|---|
| 1–20 workers | 1 | 1 | Within 1/4 mile or 5 minutes |
| 21–40 workers | 2 | 2 | Within 1/4 mile or 5 minutes |
| 41–60 workers | 3 | 3 | Within 1/4 mile or 5 minutes |
| 61–80 workers | 4 | 4 | Within 1/4 mile or 5 minutes |
Source: Cal/OSHA Title 8 §3457 field sanitation. Moving crews often use towable units. See seasonal porta potty rentals and the porta potty rental cost guide for 28-day prices.
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Questions customers ask before booking
Real questions from our customer calls, answered by our dispatch team.
How many do I need for 100 people for 4 hours?
2 porta potties. 100 × 4 ÷ 250 = 1.6, rounded up to 2. If you serve alcohol, add 1 more, and add 1 hand wash station if food is served.
Is 1 porta potty enough for a backyard party?
Yes for up to about 62 guests over 4 hours, or 125 guests over 2 hours. Past that, add a second unit so lines stay short.
Do I really need an accessible unit for a private party?
Our recommendation is yes whenever older guests, guests with walkers or strollers attend. Public events with clusters must follow the 5%-per-cluster rule in 2010 ADA Standards §213.2; confirm with your venue.
How many toilets for 25 workers?
2 toilets per sex under Cal/OSHA §1526, since 25 is more than 20. With weekly service, that keeps each unit at about 12 users, so ask about a second weekly visit.
Should I round up or down?
Always round up. A count of 2.1 means 3 units. The cost of 1 extra unit is small next to a 20-minute line.
Does a long event need a service visit?
Events of 2 days or more with heavy use often need a mid-event service, from $65 per unit. It is a typical starting price as of October 2026; your itemized quote is final.