Calculator inputs
Fields adapt to screen size automatically.
Formula used
This calculator estimates total light output needed using the lumen method: Required Lumens = (Target Illuminance × Area) ÷ (UF × MF).
- Target Illuminance is your brightness goal in lux (or converted from foot-candles).
- Area is the floor area of the space in square meters.
- UF (utilization factor) reflects how efficiently light reaches the work plane.
- MF (maintenance factor) accounts for dirt, aging, and lumen depreciation.
How to use this calculator
- Select an area method, then enter dimensions or total area.
- Choose a room preset or type a custom illuminance target.
- Set UF and MF based on room finishes and maintenance plan.
- Optional: enter fixture or lamp details to estimate fixture count.
- Press Submit to view results above the form.
- Use the CSV/PDF buttons to export the latest calculation.
Example data table
| Space | Area (m²) | Target (lux) | UF | MF | Required lumens (lm) | Fixture lumens (lm) | Estimated fixtures |
|---|---|---|---|---|---|---|---|
| Office | 48 | 500 | 0.60 | 0.80 | 50,000 | 3,500 | 15 |
| Corridor | 30 | 100 | 0.50 | 0.80 | 7,500 | 2,500 | 3 |
| Warehouse | 300 | 200 | 0.55 | 0.75 | 145,455 | 18,000 | 9 |
Example values are illustrative. Always verify targets against project specs.
Built for quick estimates and clear reporting on site.