How to use this calculator
- Enter or choose people present.
- Enter or choose capacity.
- Enter or choose alert level.
- The occupancy updates as you type. Use Copy result or Share to keep it.
Method
Occupancy % = People ÷ Capacity × 100; Spaces left = Capacity − People; Alert headcount = ⌊Capacity × Alert% ÷ 100⌋
- Capacity
- the maximum number allowed
- Alert%
- the level at which you start managing entry
Worked example
- Occupancy = 450 ÷ 600 × 100 = 75%.
- Spaces left = 600 − 450 = 150.
- Alert at 600 × 90% = 540 people.
With 450 of 600 inside, the venue is 75% full, with 150 spaces left and 90 more admissions before the alert level.
What the result means
Keep entry and exit counts running through the event; the occupancy at any moment is entries minus exits.
Assumptions and limits
- The headcount is accurate at the moment you enter it.
- Capacity limits can apply to each room or zone separately, not just the whole venue.
Questions
Where does the capacity figure come from?
Usually from the venue’s licence or fire risk assessment. This calculator does not set it.
Why set an alert level?
Queues and groups arrive in bursts. Slowing entry at 85–90% avoids going over the limit.