How Many Porta Potties Do I Need? An Arizona Event Guide

The baseline formula.

For a 4-hour dry event: 1 standard porta potty per 50 guests.

For a 4-hour event with alcohol: 1 per 40. Alcohol increases restroom traffic by roughly 25%.

For a full-day event (8+ hours): add one unit per every 3 units in your baseline.

ADA units are separate math.

Under public event codes and 2010 ADA standards, you need at least 1 ADA-compliant unit for every 20 standard units, with a minimum of 1 ADA unit per event. This is not optional for public events.

Handwashing is separate too.

If food is served, plan on 1 portable handwashing station per 8–10 porta potties — or upgrade to units with built-in sinks. Maricopa County health inspectors will look for this.

Phoenix-specific tweaks.

Summer events (June–September): add 15% to your count. Heat drives water consumption and restroom traffic.

Outdoor weddings with a bar and dance floor: upgrade at least the guest-facing count to deluxe or luxury restroom trailer.