Lighting Calculator
Calculate required lumens and wattage based on room type and dimensions.
What is Lighting Calculator
Get a defensible lumens target instead of guessing bulb counts: choose from six room presets with recommended lux levels — kitchen and study at 400, living and dining at 200, bathroom at 150, bedroom at 100 — enter length and width, and read the target lux, total lumens and a suggested LED wattage.
How to use Lighting Calculator
- Choose the room type from the dropdown
- Enter the room length and width in metres
- Read the recommended lux, total lumens and wattage
Frequently asked questions
How is total lumens calculated?
Target lux × floor area — a 20 m² living room at the 200-lux preset needs about 4,000 lumens of combined output across all fittings in the room.
How does the wattage estimate work?
Lumens are divided by a typical LED efficacy (roughly 80–100 lm/W). Actual bulbs vary, so check the lumens printed on the packaging rather than trusting watts alone.
Is one bright fitting enough?
Usually not — task zones like kitchen counters or desks want their own light on top of ambient lumens. The figure is a whole-room target, best split across several sources.
Is Lighting Calculator free?
Lighting Calculator is completely free — open the page and use every feature with no hidden charges.
Do I need to download or install Lighting Calculator?
No download or installation is needed. It is an online tool that runs in the browser on your phone, tablet and computer.
Do I need an account to use Lighting Calculator?
No. Use the tool right away — no account or sign-in required.
Does Lighting Calculator work on mobile?
Yes. The page is fully responsive and works on phones, tablets and desktop browsers.