Porta Potty Calculator for Events and Job Sites
Rough in the number of portable toilets and handwashing stations for your event or job site before you call. Final counts are settled on the phone.
Planning estimate only. Venue rules, permits and workplace regulations may require different numbers. Verify requirements with the authority that applies to you.
Use the number as a starting point
No formula knows your venue. Crowds arrive in waves, nearby buildings may share restrooms, cities and parks may set minimums, and a crew working through a hot afternoon may need more units than a ratio suggests.
Bring the estimate to the call with your venue, dates and access notes, and we will tune it together. Planning a reception? See wedding restroom options. Need accessible units? Read about ADA portable toilet rental.
Calculator questions
How many porta potties do I need for 100 guests?
For about 100 guests at a four-hour event, two standard units is the common starting point, based on the rule of thumb of roughly one toilet per 50 people. Add a third if the party runs longer, serves alcohol or includes a full meal, since all three push usage up quickly. Plan on a handwashing station for every four or five toilets, and remember that an accessible unit counts toward the total. Our porta potty calculator gives a quick estimate for other headcounts and durations. See the full porta potty quantity guide for other guest counts.
How many porta potties does OSHA require on a construction site?
Under OSHA 29 CFR 1926.51(c), a crew of 20 or fewer needs at least one toilet. Above 20 workers, the table calls for one toilet seat and one urinal per 40 workers, and at 200 or more it becomes one seat and one urinal per 50. Handwashing is expected wherever toilets are provided. Twenty-one states run their own OSHA State Plans covering private employers, and those rules can differ in detail, so confirm the current requirement with your safety manager. See our job-site toilet rental page for more. Our OSHA porta potty requirements guide covers the details.
How many ADA-accessible portable toilets do I need?
The 2010 ADA Standards say that where portable toilets are clustered in one location, at least 5 percent of the units in each cluster, and never fewer than one, must be accessible. A cluster of eight standard units therefore still needs one accessible unit, and a cluster of 30 needs two. Accessible models have a wide door, grab bars and enough interior turning room for a wheelchair, and they need a level, firm route to reach them. Some states add stricter codes, so check with your venue or permit office. More detail is on our accessible restroom rental page. More in the ADA porta potty requirements guide.