Tools · TOOL · REV 2026-10-06
Seating capacity calculator
Net area divided by seat centres and row spacing. Wheelchair spaces are then subtracted so they are not counted twice.
What this gate is
Count = floor of (length × width × (1 − aisle fraction) ÷ (seat centres × row spacing)).
This is not an egress calculation, not a C-value, and not the aisle width a code requires.
What is published now
The equation is visible
The calculator writes the law above the result so it can be checked.
Limits are written
Each tool names what it ignores: the room, the code, or the manufacturer’s sheet.
An editable example
The starting values are for understanding. Change them to your project, then discard the result when a measurement arrives.
When to open this gate
Before a meeting
To turn a verbal dispute into a calculation whose assumptions everyone can see.
Not in a tender
A result from this page is not pasted into a bill of quantities.
How to read the subject
- 01
A hall 24 × 18 m, 560 mm centres, 950 mm rows, 18% aisles: read the result, then draw a section.
- 02
Read the warning under the result. If the assumption does not apply, stop.
- 03
Replace any textbook coefficient with a laboratory sheet or a measurement.
- 04
Ask it again inside the project brief: what is success, and in which room condition?
What this gate does not do
Copying the figure
A figure without the volume, the distance, or the condition is meaningless in a contract.
Mixing tools
Adding decibels is not RT60, and throw ratio is not brightness.
SEATS
Preliminary seat count
Count = floor of net area ÷ (seat centre × row spacing), then wheelchair spaces are subtracted so they are not counted twice. This is not an egress calculation, a sightline study, or a local code.
A preliminary figure for understanding and comparison. Not a measurement, not an acoustic model, and not something to paste into a specification or a quotation.
Questions designers and owners ask
Is the result approved?
No. It is a preliminary calculation on a stated assumption.
Why are there no product numbers?
Because a product’s performance is copied from its test report, not from an article.
Can I save the calculation?
Copy the result into the study brief. The page does not send it to a server.
Technical sources
- The law written inside the tool
The law written inside the tool
- ISO 3382-1 and IEC 60268-16 when the subject is the room
ISO 3382-1 and IEC 60268-16 when the subject is the room
- The local code and the manufacturer’s sheet
The local code and the manufacturer’s sheet
Last editorial review: 2026-10-06. Review means the text was checked, not that a project was measured.
Turn the question into a brief
A study starts from room volume, use, and existing condition, not from a product name. Fill the brief and copy it.
Project study form