Whether you’re getting ready to tie the knot and need to accommodate dozens of guests, or you’re a project manager gearing up for a construction build-out, you’re likely thinking about porta potty rentals. There’s no better way to accommodate large groups without overwhelming the plumbing of an existing building, but sometimes it can be confusing to know how many you need. Too few portable toilets mean long lines and uncomfortable guests or workers, while too many results in flushed dollars. Luckily, following a few basic guidelines can help you determine the answer.

Your crowd size will be the biggest deciding factor as you rent porta potties. Construction sites should make accommodations for all workers, while events should consider how large their crowd will be. Be sure to also consider how many hours or days your event will last.

As a general rule of thumb, you should provide at least one restroom per every 100 people in attendance. If the event lasts longer than five hours, this number increases to two. If alcohol is being served, add 15–20% more restrooms. You will also need to provide one handicap-accessible restroom for every 20 portable toilets that are available. Also, keep in mind that you will need a minimum of one hand-washing station per every four restrooms.

If you’re planning your wedding or another special event, try to wait until closer to the big day to order your porta potty rental. By this point, you should have a good idea of how many guests will be attending your wedding, as well as vendors that might need to relieve themselves.

If you’re planning a public event such as an arts festival or sporting event, it’s always better to overestimate than underestimate your crowd size. Base your projection off of past events or similar events that have taken place in the area, and go for the high end of what you predict crowd size to be.

A helpful tip to remember: While having more attendees than usual is exciting for ticket sales, it’s bad news for guests that need to deal with long lines for the restroom because you didn’t order enough porta potties!

When it comes to clean and efficient portable toilets, Econ-O-Johns in Waterloo, IL, has you covered. They provide porta potty rentals to the Waterloo, Columbia, and Belleville areas, with three portable toilet models available: flushing, handicap, and standard. Units are available for rent on a daily, weekly or monthly basis, and each is thoroughly sanitized and equipped with antiseptic cleanser and paper towels. Learn more about their services online or by calling (618) 939-3001.