CalcVerse

Event Seating Capacity Calculator

Theatre-style capacity is seats per row times rows: the width left after aisles divided by the seat width, and the depth left after clearances divided by the row spacing.

Also called: Chair layout calculator · Theatre-style capacity calculator

  • Last updated
  • Formula tested against reference values

Your numbers

Use the same unit, metres or feet, for every length.

Example value; measure your chairs.

Example value; your local fire or building code may set a minimum clear gap.

Example value; check the minimum your local code requires.

Result

Seats that fit
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Calculating…

Seats per row
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Rows
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Room area per seat (your unit squared)
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Share of the floor used by seating blocks
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How to use this calculator

  1. Enter or choose room width (across the rows).
  2. Enter or choose room depth (front to back).
  3. Enter or choose stage and front clearance.
  4. Enter or choose rear clearance (cross aisle).
  5. Enter or choose seat width, centre to centre.
  6. The seats that fit updates as you type. Use Copy result or Share to keep it.

Method

Seats per row = ⌊(Width − Aisles × Aisle width) ÷ Seat width⌋; Rows = ⌊(Depth − Front − Rear) ÷ Row spacing⌋; Seats = Seats per row × Rows

Seat width
chair width plus any gap, centre to centre
Row spacing
distance from the back of one row to the back of the next

Worked example

  1. Width for seats = 20 − 2 × 1.2 = 17.6 m; 17.6 ÷ 0.5 = 35.2, so 35 per row.
  2. Depth for rows = 30 − 5 − 2 = 23 m; 23 ÷ 0.9 = 25.6, so 25 rows.
  3. Seats = 35 × 25 = 875.

A 20 × 30 m room with a 5 m stage zone, two 1.2 m aisles, 0.5 m chairs and 0.9 m rows seats 875 people theatre-style.

What the result means

This is a geometric fit. The number you may actually admit is the lower of this figure and the legal occupancy limit set for the room by the fire or building authority.

Assumptions and limits

  • A rectangular room with straight rows and aisles running front to back.
  • All lengths are in the same unit.
  • Fire codes also limit seats per row between aisles, exit widths and travel distances; these are not checked here.
  • Pillars, AV desks and wheelchair spaces must be subtracted separately.

Questions

How much space per person for theatre seating?

The answer here shows it for your layout. Planners often work from a figure per person, but codes and venues differ, so use your own measurements.

Does this give the legal capacity?

No. Only the authority that licenses the venue sets its maximum occupancy.