Room Lighting Lumens
Translate a chosen illuminance target into fixture quantity.
Your numbers
Fixture count
Lumen-method estimate, not a lighting simulation. Glare, daylight, task placement and electrical design require separate review.
Scenario comparison
Up to three snapshots in this tab. Loading one replaces the current inputs.
Formula
Use N = ceil(AE/(Φum)). A is area in m², E is chosen illuminance in lux, Φ is lumens per fixture, and u and m are utilization and maintenance factors. ceil rounds up to whole fixtures.
Translate a chosen illuminance target into fixture quantity.
Worked example
- Net area (m²)
- 20
- Chosen illuminance target (lux)
- 300
- Lumens per fixture
- 1000
- Utilization factor
- 0.6
- Maintenance factor
- 0.8
- Fixture count
- 13
- Required installed lumens
- 12,500 lm
Scope and limitations
Lumen-method estimate, not a lighting simulation. Glare, daylight, task placement and electrical design require separate review.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.
Formula version: f83778c8399f · Example checked: