Online Tool Store
Room Lighting Calculator
Calculate required lumens and fixture count using room type, Lux presets, room dimensions, and wall-color reflectance.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Total Lumens Required
Recommended Fixtures
Approx. LED Power Draw
Assuming ~90 lm/W efficiency
How it works
- Select your room type to apply standard architectural illuminance guidelines (or specify a custom Lux level).
- Enter the length and width of the room in meters or feet.
- Choose the brightness rating of your planned light bulbs (e.g. 800 lumens for standard 9W LED bulbs).
- The calculator computes total lumens required and the exact number of fixtures needed.
The formula
Total Lumens = Room Area (m²) × Target Illuminance (Lux) × Reflectance Multiplier Fixture Count = ⌈Total Lumens / Lumens per Fixture⌉
FAQ
What is the difference between Lumens and Lux?
Lumens measure the total amount of visible light emitted by a light source. Lux measures illuminance — the intensity of light falling on a surface area (1 Lux = 1 Lumen per square meter).
How many lumens do I need for a typical living room vs kitchen?
A living room generally requires soft ambient lighting around 150 Lux (~1,500 to 3,000 lumens for an average room). A kitchen requires higher task illumination of 300 to 500 Lux (~4,000 to 8,000 lumens) to ensure safe food preparation.
How does wall color affect lighting requirements?
Dark paint colors and textured surfaces absorb light rather than reflecting it. Rooms with dark accent walls typically require 15% to 30% more lumens to achieve the same perceived brightness as white or pastel rooms.
How many LED watts equal 1,000 lumens?
Modern LED bulbs typically produce 80 to 100 lumens per watt. Therefore, a 1,000-lumen output requires approximately 10 to 12 watts of LED power compared to a 75-watt traditional incandescent bulb.
How we compare
| Feature | Online Tool Store | Lighting store estimators | Rule of thumb charts |
|---|---|---|---|
| Architectural Lux presets by room function | ✓ | Partial | ✗ |
| Wall paint reflectance compensation | ✓ | ✗ | ✗ |
| LED total wattage estimation | ✓ | ✓ | ✗ |