How many porta potties do I need for an event?

For a typical event of about four hours, plan on roughly one portable restroom for every 50 guests. Longer events, an open bar or a crowd that arrives and leaves all at once push that number up. Short events can get by with fewer.

There is no single law that sets the number of restrooms for a private party. The figures below are a common rule of thumb in the rental business, and a sensible place to start. If your event needs a permit, the permit may set its own count, and that count wins.

Rule of thumb, not a law. These counts assume a mixed adult crowd, no alcohol and restrooms serviced before the event. Your permit, venue or contract can ask for more.

Count accessible units inside these totals, not on top of them, as long as you meet the ADA minimum below. A restroom trailer with two or three stalls counts as two or three restrooms, and it takes up less room than the same number of single units.

• Alcohol: people use the restroom more often when there's a bar. As a rule of thumb, add 15 to 20 percent more units, rounded up.
• Food: wherever food is served, guests and staff need a place to wash their hands. Put a hand washing station near the food and one by each group of restrooms.
• Crowd mix: women's lines are the ones that back up. If the crowd is mostly women, round up; if it is mostly men, a unit with a urinal moves the line faster.
• Timing: a crowd that all breaks at once, like a ceremony ending or halftime, needs more units than the same crowd spread over an afternoon.
• Multi-day events: units need cleaning and pumping between days. Plan service each night, or more units if service isn't possible.

Where portable toilets are grouped together for the public, the 2010 ADA Standards for Accessible Design require at least 5 percent of the units in each group to be accessible (§213.2, exception 3). Percentages are rounded up to the next whole unit (§104.2), so any group of restrooms needs at least one accessible unit.

The accessible unit must be labeled with the wheelchair symbol, have room to turn around inside, and sit on an accessible route: firm, level ground with no step, curb or loose gravel in the way. The U.S. Access Board's guide to toilet rooms explains what the unit and the path to it need. Our ADA portable restroom has a level entry and room to turn. For more detail, read our ADA guide.

Public events, street fairs and events on rented land often need a permit from the city or, outside city limits, from the county. In Santa Barbara and San Luis Obispo counties, the permit or the venue may set how many restrooms and hand wash stations you must have. Ask what your permit requires before you finalize the count; we can send a written equipment list for your application.

Wineries and private estates often have their own rules too: where trucks can drive, how close units can go to the tasting room, and when delivery is allowed. If you're planning a wedding, see our guide to restroom trailers in the Santa Ynez Valley.

Standard porta potties are the workhorse for festivals, sports days and fundraisers. Deluxe units are roomier, with a nicer finish, for parties where guests are dressed up. Restroom trailers have separate stalls and running water, and they suit weddings and winery dinners. Many events mix them: a trailer near the tables, single units and an ADA unit near the parking.

• Keep restrooms close enough to find but downwind of the food and the dance floor.
• Group them, so the service truck can reach every unit and the line is in one place.
• Leave a clear driveway: our truck has to get within reach of each unit to pump it.

We deliver across the Central Coast from our yard in Lompoc, including Santa Barbara, Solvang, San Luis Obispo and Paso Robles. Send us the guest count, the hours and the address through the quote form and we'll recommend a mix and call you back with a price.