How many porta potties do I need for my event?
For an event up to 4 hours, you need 1 standard porta potty per 50 guests. Add 1 unit per 100 guests if the event runs 4 to 8 hours, and 1 more per 100 guests if alcohol is served. Round each step up to a whole unit.
- Base: guests ÷ 50, rounded up.
- 4 to 8 hours: add guests ÷ 100, rounded up.
- Alcohol: add guests ÷ 100, rounded up.
- Accessible units: at least 5% of each cluster, minimum 1 at public events.
- Hand wash stations: 1 per 4 toilets, rounded up, minimum 1 if food is served or 50+ guests attend.
This is our planning method, based on the widely used portable sanitation industry event chart. Enter your numbers below and the calculator does the math.
Method: 1 unit per 50 guests up to 4 hours; add 1 per 100 guests for 4–8 hours and again for alcohol; 5% accessible (2010 ADA Standards 213.2, minimum 1); 1 hand wash station per 4 toilets. Job sites: OSHA 29 CFR 1926.51 Table D-1.
Event chart: porta potties for 50 to 1,000 guests
A 100-guest event needs 2 porta potties for up to 4 hours and 3 for 4 to 8 hours. A 500-guest event needs 10 units for up to 4 hours and 15 for 4 to 8 hours. These counts assume no alcohol; the accessible units are part of each total.
| Guests | Toilets, up to 4 h | Accessible (of those) | Hand wash | Toilets, 4-8 h | Accessible (of those) | Hand wash |
|---|---|---|---|---|---|---|
| 50 | 1 | 1 | 1 | 2 | 1 | 1 |
| 75 | 2 | 1 | 1 | 3 | 1 | 1 |
| 100 | 2 | 1 | 1 | 3 | 1 | 1 |
| 150 | 3 | 1 | 1 | 5 | 1 | 2 |
| 200 | 4 | 1 | 1 | 6 | 1 | 2 |
| 250 | 5 | 1 | 2 | 8 | 1 | 2 |
| 300 | 6 | 1 | 2 | 9 | 1 | 3 |
| 400 | 8 | 1 | 2 | 12 | 1 | 3 |
| 500 | 10 | 1 | 3 | 15 | 1 | 4 |
| 750 | 15 | 1 | 4 | 23 | 2 | 6 |
| 1,000 | 20 | 1 | 5 | 30 | 2 | 8 |
Hand wash counts assume food is served or at least 50 guests attend. For an all-day event of more than 8 hours, call dispatch; we usually add units and schedule service during the event.
Ready to book or price it out?
A local dispatcher answers Mon–Sat, 7 a.m.–7 p.m.. Have your ZIP, dates and headcount ready, and you get an itemized price on the call.
How does serving alcohol change the count?
Serving alcohol adds 1 porta potty per 100 guests, rounded up, on top of the base and time adjustments. A 300-guest, 5-hour festival with beer needs 12 units: 6 for the base, 3 for the longer hours and 3 for alcohol. That cluster also needs 1 accessible unit and 3 hand wash stations.
Worked example: 300 guests, 5 hours, beer tent
| Step | Math | Units |
|---|---|---|
| Base (up to 4 h) | 300 ÷ 50 = 6 | 6 |
| 4-8 hours | 300 ÷ 100 = 3 | +3 |
| Alcohol | 300 ÷ 100 = 3 | +3 |
| Total toilets | 6 + 3 + 3 | 12 |
| Accessible (of the 12) | 12 × 5% = 0.6 → round up | 1 |
| Hand wash stations | 12 ÷ 4 = 3 | 3 |
A smaller case: 150 guests, 6 hours, with a bar. That is 3 base + 2 for time + 2 for alcohol = 7 toilets, with 1 accessible unit and 2 hand wash stations (7 ÷ 4 = 1.75, rounded up).
In July and August, Dayton highs sit in the mid-80s with humidity. Guests drink more, so events over 4 hours benefit from one extra unit or a mid-event service.
How many accessible units and hand wash stations do I need?
Plan at least 5% of the porta potties in each cluster as wheelchair-accessible, and never fewer than 1 at a public event. Plan 1 hand wash station for every 4 toilets, rounded up. A 20-unit cluster needs 1 accessible unit and 5 hand wash stations.
The 5% rule comes from the 2010 ADA Standards, section 213.2. Each group of toilets in one spot is a cluster, so units at the front gate and units by the stage each need their own accessible unit. An accessible unit also needs a 60-inch diameter turning circle or a T-shaped turning space.
Our wheelchair-accessible unit counts as one of your toilets, not as an extra. Our hand wash stations serve 2 people at once and hold about 350 washes per fill.
Confirm the final count with your venue, permit office or event safety officer. We don't give legal advice.
How many porta potties does a construction site need?
OSHA Table D-1 requires 1 toilet for 20 or fewer workers, 1 toilet seat and 1 urinal per 40 workers for 20 or more, and 1 seat and 1 urinal per 50 workers at 200 or more. Our standard unit has a seat and a urinal, and weekly service suits about 10 workers per unit.
The legal minimum is in OSHA 29 CFR 1926.51(c), Table D-1. Washing facilities are covered in 1926.51(f). Our recommendation is separate from the law: on a 40-hour week, one weekly service handles about 10 workers per unit. Add a second weekly service for $45 when a unit serves more than 10.
| Workers | OSHA Table D-1 minimum | Our weekly-service recommendation (units) |
|---|---|---|
| 10 | 1 toilet | 1 |
| 20 | 1 toilet | 2 |
| 30 | 1 toilet seat + 1 urinal | 3 |
| 40 | 1 toilet seat + 1 urinal | 4 |
| 60 | 2 toilet seats + 2 urinals | 6 |
| 80 | 2 toilet seats + 2 urinals | 8 |
| 100 | 3 toilet seats + 3 urinals | 10 |
| 150 | 4 toilet seats + 4 urinals | 15 |
| 199 | 5 toilet seats + 5 urinals | 20 |
| 200 | 4 toilet seats + 4 urinals | 20 |
| 250 | 5 toilet seats + 5 urinals | 25 |
Note the odd step at 200 workers: the ratio changes from 1 per 40 to 1 per 50, so 199 workers need 5 and 200 need 4. More units still mean shorter lines and cleaner toilets. See construction porta potty rental for weekly service plans, and check with your safety officer.
How many porta potties does a farm crew need?
Under OSHA 1928.110, a farm with 11 or more hand laborers in the field needs 1 toilet and 1 handwashing facility for every 20 workers, or fraction of 20. Both must be within a quarter-mile walk of each worker. Crews working 3 hours or less, including travel, are exempt.
Read the rule in OSHA 29 CFR 1928.110. A 25-person picking crew needs 2 toilets and 2 hand wash stations, set together near the work. When terrain blocks a quarter-mile walk, the rule allows placement at the nearest point a vehicle can reach.
Crews that move from field to field often use a towable unit on a small trailer; ask dispatch for a quote. Seasonal farm rentals run on our 28-day long-term plan with weekly service.
How many restroom trailer stalls do I need?
Size a restroom trailer by counting each toilet stall as 1 porta potty in the event chart. A 100-guest, 4-hour party needs 2 stalls, so a 2-stall trailer works. The same party running 6 hours with a bar needs 4 stalls, so step up to a 4-stall trailer.
| Guests | Up to 4 h | 4-8 h | 4-8 h with alcohol |
|---|---|---|---|
| 50 | 1 → 2-stall | 2 → 2-stall | 3 → 4-stall |
| 100 | 2 → 2-stall | 3 → 4-stall | 4 → 4-stall |
| 150 | 3 → 4-stall | 5 → 4-stall + 1 unit | 7 → Two 4-stall |
| 200 | 4 → 4-stall | 6 → 4-stall + 2 units | 8 → Two 4-stall |
When the count falls between sizes, adding one or two flushing porta potties near the dance floor is cheaper than a second trailer. Trailers have steps, so add a wheelchair-accessible unit for guests who need one. Compare options on the restroom trailer rental page.
Common questions
How many people does one porta potty accommodate?
One standard porta potty serves about 50 guests at an event up to 4 hours. Longer events and alcohol each add 1 unit per 100 guests. On a job site, one unit with weekly service suits about 10 workers.
For a one-day event of about 50 people, is one unit enough?
One unit is enough for 50 guests at an event up to 4 hours with no alcohol. If the party runs 4 to 8 hours or has a bar, plan 2 units, plus a hand wash station if food is served.
How many porta potties do I need for 100 guests?
100 guests need 2 porta potties for an event up to 4 hours, 3 for 4 to 8 hours, and 4 for 4 to 8 hours with alcohol. One of them should be wheelchair-accessible at a public event, plus 1 hand wash station.
How many porta potties for a wedding of 150?
A 150-guest wedding lasting 6 hours with a bar needs 7 toilets: 3 base, 2 for time and 2 for alcohol. Include 1 wheelchair-accessible unit and 2 hand wash stations. See our wedding porta potty page for layout ideas.
Does a wheelchair-accessible unit count toward my total?
A wheelchair-accessible unit counts as one of your toilets. For 7 total units, plan 6 standard or deluxe units plus 1 accessible unit, not 7 plus 1.
How many hand wash stations do I need?
Plan 1 hand wash station per 4 toilets, rounded up, with at least 1 when food is served or 50+ guests attend. Twelve toilets need 3 stations.
Can I order fewer units and add service instead?
A $45 mid-event service empties and restocks units, which helps on long or multi-day events. Service does not shorten lines at peak times, so do not drop below the base 1-per-50 count.