Occupant load calculator
Floor area and use: you get the occupant load from area per person, the number of exits by the general rule and total egress width.
Occupant load
20 people
- Occupant load20 people
- Occupant load factor10 m²/person
- Exits (general rule)1 unit
- Total egress width (P ÷ 200)2.625 ft
Your prices per language/currency. Used when you enable “Use my prices” in calculators. My prices →
How it's calculated (visible formula)
occupant load = ceil(floor area ÷ area per occupant)
- Net geometric measurement, no waste.
- Adjustable waste % for cuts and breakage.
- Purchase rounded up to sellable units (boxes, bags, buckets, boards).
How to calculate it, step by step
- Measure the area of each zone.
- Pick each zone's use (office, retail, restaurant…).
- Divide area by the load factor for that use.
- Add up all zones.
- Use the total to check exits and egress widths.
Load factors used (Spanish CTE, similar order to IBC)
| Use | m² (sq ft) per person |
|---|---|
| Residential | 20 (215) |
| Office | 10 (108) |
| Classroom | 1.5 (16) |
| Retail ground floor | 2 (22) |
| Restaurant seating | 1.5 (16) |
| Gym with equipment | 5 (54) |
| Storage | 40 (430) |
Worked example: 2,150 sq ft office
- 200 m² ÷ 10 m² per person = 20 people
- ≤ 100 occupants: one exit (general rule)
→ Occupant load of 20.
Common mistakes
- Using gross area where net is required (or vice versa).
- One use for mixed spaces.
- Confusing design occupant load with posted capacity.
Pro tips
- Calculate by zone in mixed spaces (dining, kitchen, storage).
- Accessory spaces may use different factors.
- If the posted capacity is lower, follow it.
- Recalculate when the use changes.
From calculation to quote
Add labour, overhead and your margin, and generate the professional PDF.
FAQs
- What is the IBC load factor for offices?
- 150 sq ft gross per occupant (business areas).
- Restaurants?
- 15 sq ft net per occupant for unconcentrated tables and chairs.
- When are two exits required?
- IBC Table 1006.2.1 sets single-exit limits, often 49 occupants.
- Does a restaurant kitchen count?
- Yes, at the kitchen load factor (200 sq ft gross per person in the IBC).
- Occupant load vs capacity?
- Capacity is the posted limit; occupant load is the design value for egress.
- Standing-room factor?
- 5 sq ft net per person in the IBC.
Sources and standards
Maintained by Srikanta M · Formula v1.0.0 · Verified 2026-09-10 · Updated 2026-09-10 · Limits: quantity estimation, not structural design or site supervision.