How Many Portaloos Do You Need? Australian Planning Ratios

Getting the number wrong is expensive in both directions. Too few units and you get queues, complaints and a genuine amenity problem. Too many and you have paid delivery, servicing and collection on cabins nobody used.

Start with the baseline ratio

Two different baselines apply depending on the job.

Events: one standard portaloo per 50 people for an event up to four hours. This is the figure most Australian suppliers plan from.

Construction and workplaces: one toilet per 10-15 workers, with handwashing provided alongside. Australian WHS regulations require adequate facilities and set outcomes rather than a single prescribed ratio, so treat this as planning guidance and confirm your obligations with your jurisdiction's regulator.

Adjust for the things that actually change usage

The baseline assumes an average crowd doing average things. Adjust upward when:

• The event runs longer than four hours. Add roughly 25% for each additional four-hour block.
• Alcohol is served. Consumption drives usage up substantially — add 25-40%.
• Food is served. A similar effect, though smaller than alcohol.
• The audience skews female. Longer average cubicle time means more units for the same headcount, or a higher proportion of cubicles to urinals.
• There are no other facilities nearby. If your portaloos are the only option, they carry the entire load.
• It is hot. More drinking means more usage.

Adjust downward only when there are permanent toilets on site genuinely available to the same crowd.

Worked examples

Job	Headcount	Duration	Suggested plan
Community fun run	300	3 hours, no alcohol	6 standard, 1 accessible, 2 handwash
Wedding	120	6 hours, alcohol	3 standard or a 2-stall luxury trailer, 1 handwash
Festival day	2,000	8 hours, alcohol	30+ mixed cubicles, urinal pods, 2+ accessible, attendant servicing
House build	8 workers	4 months	1 standard, 1 handwash, weekly service
Civil project	40 workers	12 months	3-4 standard, urinal, 2 handwash, twice-weekly service

Do not forget the non-toilet units

Handwash stations are required alongside toilets on worksites and expected at any event serving food. They are inexpensive relative to the toilets.

Urinals are the cheapest way to cut queue times at large events with a significant male audience. A urinal pod handles far more throughput per dollar than an equivalent cubicle.

Accessible units need to be planned as a separate line, not counted within your standard total. For any public event, include at least one.

Then ask the supplier

Every figure above is a planning starting point, not a compliance calculation. Send the supplier your headcount, hours, alcohol and food arrangements, audience profile, site access and whether other facilities exist. An experienced operator will adjust the mix and will tell you if your numbers look wrong — they have seen your event type before.

For what those units will cost once you have the count, see the portable toilet hire cost guide.