Lighting Calculator (Lux → Lumens)
Lumens and LED watts needed to light a room.
Rule-of-thumb estimate – check the exact values for your situation.
Runs entirely in your browser. Nothing is sent anywhere.
How it works
- 1Enter your values.
- 2See the result update instantly as you type.
- 3Change any value to compare scenarios.
About this tool
Lighting Calculator (Lux → Lumens): Lumens and LED watts needed to light a room. Type your numbers and the result is calculated instantly — no button to press, nothing to install. All math runs locally in your browser, so the values you enter are never sent anywhere.
Example
| Input | |
|---|---|
| Room area (m²) | 20 |
| Room type (target illuminance) | Hallway, dining (150 lx) |
| LED efficacy (lm/W) | 100 |
| Result | |
| Lumens needed | 6,250 lm |
| LED power | 62.5 W |
| Illuminance | 150 lx |
How do I use the Lighting Calculator (Lux → Lumens)?
Enter your values. See the result update instantly as you type. Change any value to compare scenarios.
Is the Lighting Calculator (Lux → Lumens) free?
Yes. It is completely free with no sign-up, no usage limits and no watermark.
Is my data sent to a server?
No. Everything is calculated locally in your browser. Nothing you enter is uploaded, logged or stored.
Does it work on my phone?
Yes. It works in any modern browser on Android, iPhone, iPad, Windows, Mac and Linux — no app needed.