Portable Toilet Count Calculator
Estimate how many portable restrooms to rent for an event based on guest count, event length and alcohol service.
How it works
Units = (guests ÷ 50) × (hours ÷ 4) × (1.15 if alcohol) · rounded up · + 1 accessible (ADA)
The standard rental guideline is one portable restroom per 50 guests for an event of about four hours. Longer events and alcohol both raise usage — alcohol adds roughly 15% because guests drink and use facilities more — so the count scales with hours and gets a bump when a bar is open. At least one ADA-accessible unit is expected at public events and is good practice everywhere; it is counted on top of the standard units.
Worked example
For 150 guests over 5 hours with alcohol: (150 ÷ 50) × (5 ÷ 4) = 3.75, then × 1.15 = 4.31, rounded up to 5 standard units. Add 1 accessible unit for 6 total — about 30 guests per standard unit.
Frequently asked questions
How many portable toilets do I need per person?
The rule of thumb is one unit per 50 guests for a four-hour event. Scale up for longer events and add about 15% when alcohol is served, since people drink more and use restrooms more often.
Do I need an accessible (ADA) unit?
Public events are generally required to provide at least one ADA-accessible restroom, and it is considered best practice for any event. Accessible units are larger and counted separately from standard units.
Should I add hand-washing stations?
Yes. Many rental companies recommend one hand-wash or sanitizer station per two restrooms, and food service often requires them. They are booked separately from the toilet units themselves.
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This calculator is for educational purposes. Double-check important results before acting on them.