Separate total attendance from peak use
Explain how many people are present together, how long they stay and whether demand concentrates at breaks. For a project, include overlapping trades and shifts. For an event, include the organisers, vendors and helpers who use the facilities outside guest hours.
If the estimate is uncertain, explain the likely range and when you expect better information. Ask when changes to the proposed quantity can be reviewed; do not silently rely on the earlier estimate after plans grow.
Describe other facilities and specific needs
Identify permanent toilets that are genuinely available to your group, including their opening hours and access restrictions. Ask how accessible provision and washing fit into the recommendation rather than adding them as an afterthought.
A trailer and a set of individual cabins should not be compared only by their exterior size. Ask the provider to explain the offered arrangement and its service implications.
Review the recommendation with servicing and layout
Discuss the period of use and any practical limits on maintenance access. Check that the property has suitable positions for the proposed equipment and that users can reach them. A calculated quantity is not helpful if the equipment cannot be placed or maintained appropriately.
This guide intentionally does not publish a universal ratio. Request an assessment for your North Miami location, and have the responsible organiser check any requirements that apply to the activity.