Lux To Nits Calculator
Convert illuminance (Lux) to luminance (Nits/cd/m²) based on surface reflectance. Essential for display calibration, photography, and lighting design.
Convert between illuminance and luminance with adjustable reflectance values for accurate brightness calculations.
Illuminance Converter
Light falling on the surface
Surface reflection mode - adjust reflectance below
Advanced Settings
Conversion Results
Enter illuminance value
then click "Calculate" for luminance
Lux To Nits Calculator
Light measurements confuse many people because different units describe different things. Lux measures how much light falls onto a surface, while nits describe how bright that surface appears when you look at it. This calculator bridges the gap by converting one into the other.
The Conversion Formula
Example Conversions
| Lux | Reflectance | Nits (cd/m²) | Brightness Level |
|---|---|---|---|
| 100 lx | 80% | 25.5 | Low |
| 300 lx | 60% | 57.3 | Indoor |
| 500 lx | 80% | 127.3 | Office |
| 1000 lx | 50% | 159.2 | Office |
| 2000 lx | 90% | 573.0 | Outdoor |
| 5000 lx | 80% | 1273.2 | HDR |
| 10000 lx | 60% | 1909.9 | HDR |
Why Reflectance Matters
The same amount of light produces different brightness levels depending on the surface. A white paper under 500 lux looks much brighter than black asphalt under identical lighting. That's because white paper reflects around 80% of light, while asphalt only reflects about 12%.
This matters when you're checking if a display stays readable outdoors, planning photography lighting, or calibrating monitors. The lux reading alone doesn't tell the whole story.
Common Use Cases
- Photographers estimate how bright a subject appears under specific lighting
- Display engineers check if screens stay readable in bright environments
- Architects calculate perceived brightness of interior surfaces
- Calibrators translate between different measurement standards
For display emission mode, the calculator treats the surface as a light source. In this case, reflectance becomes irrelevant — the nits value equals the display's native luminance. Use reflected light mode when measuring surfaces that bounce light from another source.