The quick answer
For an event, send peak attendance, duration, existing facilities, food and drink plans, and a site layout before choosing a count. For a construction site, begin with the OSHA facility baseline and then check whether the units and servicing can support actual use. Attendance or worker count alone does not settle the entire rental.
1. Count the people who share the facilities
A guest list can miss vendors, staff, volunteers, and setup crews. For an Allen neighborhood celebration, consider when the most people will be present together. For a jobsite, record the busiest shift and the work areas that share each restroom group. A facility on the far side of a closed work zone may not be practically available to everyone.
2. Count the hours and the usable alternatives
Tell the team whether guests stay for a short gathering or spend most of the day onsite. List permanent toilets only if they will be open, accessible, and available to your users. Explain whether activities take place in separate locations. Do not subtract a building’s restrooms simply because they appear on a venue map.
3. Match service to demand
A multi-day festival can need pumping and restocking between sessions. The customer-call notes include an organizer asking for 12 toilets, 3 handwashing stations, and an additional service visit. That describes one requested setup; it is not a formula for all festivals. Ask when servicing is possible and whether trucks can reach the units during the event.
A construction example with the math visible
For 60 workers, the OSHA middle category gives one seat and one urinal per 40 workers. Calculate 60 ÷ 40 = 1.5, then round up: 2 toilet seats and 2 urinals. This counts fixtures, not necessarily four separate portable restrooms. Confirm the assigned model and the actual sanitary conditions. It does not imply that weekly cleaning is always enough.
Accessible units are calculated per cluster
For covered portable-toilet clusters, the Access Board guide calls for at least 5% accessible units in each cluster. A 30-unit cluster gives 30 ÷ 20 = 1.5, rounded up to 2 accessible units. If the site has two separate 10-unit clusters, calculate each separately: at least 1 accessible unit in each. The accessible route and model must also be suitable.
What to send for an Allen quote
Share the event address, dates, peak users, hours, existing facilities, and any placement restrictions. Include handwashing and accessibility requirements. Use our planning tools for the sourced calculations, then request a site-specific recommendation.