A practical planning guide from Briony Portable Toilets.
The most common question we get is a simple one: how many portable toilets do I actually need? The math is not hard, but it depends on more variables than most first-time renters realize. This guide gives you a working formula plus the real-world adjustments that separate a comfortable event from a long-line disaster.
A working baseline: one standard unit per 50 attendees for a four-hour event. Double that (one per 25) for an eight-hour event. Halve it (one per 100) for a two-hour ceremony where guests will not linger. This is the starting point, not the final number.
Add 15–25% capacity when alcohol is served. Cash bars trend lower on the multiplier, open bars higher. Beer-forward events (festivals, tailgates) require more capacity than wine-service weddings. Coffee-heavy morning events see similar demand spikes and deserve the same adjustment.
Above 85°F add 10–15% capacity — hydration drives more frequent restroom use. Below 40°F add 5–10% for winter events (cold contracts the bladder). Rain does not change per-attendee use but slows walking to units, which spreads demand over more of the event.
For events longer than eight hours, the baseline formula understates need. Two-day festivals should treat each day as a full-duration event and plan capacity accordingly. Overnight rentals — camping festivals, tailgate weekends — benefit from twice-daily service.
Attendance splits roughly 50/50 in most events, but women use restrooms roughly twice as often and take longer per visit. If you can label units by sex, allocate 60% to the women's side and 40% to the men's side. If units are all-gender, add one or two units above the base calculation to account for this asymmetry.
Add at least one ADA-compliant unit for any public event, minimum. Add handwashing stations at a ratio of one per every three restroom units, minimum one per bank. For events with sit-down meals, add a luxury trailer or family-sized unit for guests who need more space.
A five-hour outdoor wedding with 150 guests, an open bar, and summer weather: baseline is 150 ÷ 50 × (5/4) ≈ 4 standard units. Add 20% for alcohol and 10% for heat: 4 × 1.30 = 5.2, round up to 6 units. Split as 4 women's, 2 men's, or use one four-station luxury trailer plus two supplemental standard units. Add 1 ADA unit and 2 handwashing stations.
Once you have the fundamentals from this guide, the next step is a written quote tailored to your project. Call our Fargo office at 701-987-0097 or use our online quote form. Quote requests during business hours are typically returned the same business day.
Call 701-987-0097 or request a quote online. Our team will walk you through your options.
We serve the entire Fargo-Moorhead metro and Cass County. See our Areas Served page for the full list.
One to two weeks is ideal, though same-week and same-day service is often available.
Yes — every unit is pressure-washed, sanitized, and inspected between rentals.
Just call the office. We can add units, increase service frequency, or extend rentals at any time.
Call today for fast delivery and a free quote across Fargo-Moorhead.
