Lumen Calculator
How many lumens — and how many fixtures — does a space need? Enter the room size and use, and get an instant estimate based on the same IES & EN 12464-1 illuminance levels we apply to professional lighting documentation.
- Target illuminance
- 500 lux
- Area
- 24.0 m² · 258 ft²
- Lumens at task plane
- 12,000 lm
- Installed (÷ UF·MF)
- 30,000 lm
A planning estimate using the lumen method — not a photometric layout. Real projects need point-by-point calculations (DIALux / AGi32) and a compliant submittal.
Need a real photometric study or spec sheet?Recommended lux levels by space type
Lighting standards define a maintained illuminance for each task. These are the values built into the calculator — drawn from EN 12464-1 (Europe) and IES recommendations (US):
| Space | Lux | Footcandles |
|---|---|---|
| Office — general / open-plan | 500 lux | ~50 fc |
| Office — detailed / drawing work | 750 lux | ~70 fc |
| Conference / meeting room | 500 lux | ~50 fc |
| Retail — sales floor | 500 lux | ~50 fc |
| Classroom | 300 lux | ~30 fc |
| Warehouse — storage | 150 lux | ~15 fc |
| Warehouse — picking / active | 200 lux | ~20 fc |
| Industrial — assembly (medium) | 500 lux | ~50 fc |
| Industrial — fine / precision | 1000 lux | ~95 fc |
| Corridor / circulation | 100 lux | ~10 fc |
| Parking (indoor) | 75 lux | ~7 fc |
How the calculation works
The calculator uses the lumen method: required installed lumens = (target lux × area) ÷ (utilization factor × maintenance factor). The utilization factor accounts for how much light actually reaches the work plane; the maintenance factor accounts for lumen depreciation and dirt over time. It's an excellent planning estimate — but a real project still needs a point-by-point photometric layout and a compliant submittal, which is exactly what we do at Lumen Studio.
Frequently asked questions
How many lumens do I need for a room?
Multiply the room area by the recommended illuminance for its use. For a 20 m² (215 ft²) office at 500 lux you need about 10,000 lumens at the work plane — and roughly 25,000 installed lumens once you account for fixture utilization and maintenance losses. Use the calculator above to get the exact figure for your space.
What is the difference between lux and lumens?
Lumens measure the total light a source emits. Lux measures how much of that light lands on a surface — one lux is one lumen per square metre. Standards like EN 12464-1 and IES specify target lux for each task, and the calculator converts that into the lumens you need to install.
How many lumens per square meter or square foot?
It depends on the task: 100 lux (≈10 lm/ft² of delivered light) for a corridor, 500 lux for an office, 1000 lux for precision work. Because real installations lose light to fixtures and dirt, plan for roughly 2–2.5× the delivered lumens as installed lumens.
From estimate to spec-ready documentation
If you sell or specify lighting, Lumen Studio turns raw product data into catalogs, spec sheets, and compliant submittals — accurate, on-brand, and built to win.