How many porta potties do I need for an event?
In Maricopa County, plan at least 1 porta potty per 100 attendees when permanent restrooms are not adequate, within 200 feet. The PSAI chart adjusts for event length: 1,000 guests need about 4 units for 1 hour, 8 for 4 hours and 12 for 8 hours. Use the higher number.
Add 20 to 30% when it is 80F or hotter or alcohol is served, per PSAI. Count staff, vendors and volunteers. Then add accessible units: 5% per cluster federally, 10% at Mesa events.
Sources
| Source | What it says |
|---|---|
| Maricopa County Environmental Health Code, Ch. II Sec. 6 Reg. 5 | Public gatherings without adequate permanent toilets need at least 1 toilet per 100 attendees (or as the health officer requires), within 200 feet. |
| PSAI Extended Special Event Chart | Industry planning chart. Example: 1,000 guests need about 4 units for 1 hour, 8 for 4 hours and 12 for 8 hours. Add 20 to 30% when it is 80F or hotter or alcohol is served. |
| 2010 ADA Standards 213.2 Exception 3 | Where single-user portable toilets are clustered, at least 5% of the units in each cluster must be accessible, rounded up. 20 units means 1 accessible unit; 21 units means 2. |
| Mesa Special Events Handbook (rev. Jan 2026) | 1 restroom per 100 attendees, or 1 portable per 300 if permanent restrooms sit within 200 feet. At least 10% must be ADA accessible. Weddings and funerals are not special events. |
Summaries checked against the source on 2026-11-03. Always confirm with your permitting office.
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Last reviewedNovember 3, 2026. Rules are summarized from the linked government and industry sources. We re-check them before each update. See our editorial policy.