Calculate occupancy load factor, room area, or number of people from any two values, with ft², m², or yd² per person units and rounded-up people results.
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Occupancy Load Factor Formula
The occupancy load factor is the amount of floor area assigned to each person. The calculator can solve for room area, number of people, or occupancy load factor when you enter the other two values.
P = ceil(A / OLF)
A = P * OLF
OLF = A / P
- P = total number of people
- A = total room area
- OLF = occupancy load factor, in area per person
- ceil = round up to the next whole number
If you calculate the number of people, the result is rounded up because a room cannot have a fraction of a person for occupancy load purposes.
If you calculate total room area, the calculator multiplies the number of people by the occupancy load factor.
If you calculate occupancy load factor, the calculator divides the room area by the number of people.
The calculator converts square meters and square yards to square feet internally, then converts the result back to the unit you selected.
Common Occupancy Load Factor Values
Occupancy load factors depend on the building code and the exact use of the space. The values below are common reference values in square feet per person.
| Space type | Typical load factor | Meaning |
|---|---|---|
| Assembly, standing space | 5 ft²/person | Dense standing occupancy |
| Assembly, tables and chairs | 15 ft²/person | Dining or similar seated use |
| Classroom | 20 ft²/person | Typical classroom seating |
| Business area | 150 ft²/person | Office or business use |
| Storage area | 300 ft²/person | Low occupant density |
Area Unit Conversions
| Unit | Equivalent in square feet |
|---|---|
| 1 square foot | 1 ft² |
| 1 square meter | 10.7639 ft² |
| 1 square yard | 9 ft² |
Examples
Example 1: Calculate the number of people
You have a room area of 1,200 ft² and an occupancy load factor of 15 ft² per person.
P = ceil(1200 / 15) = 80
The occupancy load is 80 people.
Example 2: Calculate the required room area
You need space for 45 people using an occupancy load factor of 20 ft² per person.
A = 45 * 20 = 900
The required room area is 900 ft².
FAQ
What is an occupancy load factor?
An occupancy load factor is the floor area assigned to each person for a specific type of space. For example, an occupancy load factor of 15 ft² per person means each person is counted as using 15 square feet of area.
Why does the people result round up?
The people result rounds up because occupancy load is counted in whole people. If the calculation gives 25.2 people, the occupancy load is 26 people.
Is occupancy load the same as the allowed maximum occupancy?
Not always. Occupancy load estimates the number of occupants based on area and use. The allowed maximum occupancy may also depend on exits, door widths, plumbing fixtures, fire protection systems, and local code requirements.
