maratoolHow to convert nits to foot-lamberts (screen brightness)
Type a luminance — read nits, fL, stilbs, or lamberts instantly.
Display specs quote nits, projection standards quote foot-lamberts, and photometry texts use stilbs. The Luminance Converter moves between them with exact π-based factors.
How it works
- Pick units — "Candela per square meter / Nit (cd/m²)" to "Foot-lambert (fL)", or any other pair.
- Type a value — the result updates as you type, with swap and copy.
- Copy — one click, with "Copied!" feedback.
Luminance conversion factors
Every unit converts through the candela per square meter (the base unit). To convert A → B, multiply by A's factor and divide by B's:
| Unit | = this many candela per square meters |
|---|---|
| Candela per square meter / Nit (cd/m²) | 1 |
| Kilocandela per square meter (kcd/m²) | 1,000 |
| Stilb (sb) | 10,000 |
| Candela per square foot (cd/ft²) | 10.76391041671 |
| Candela per square inch (cd/in²) | 1,550.0031000062 |
| Foot-lambert (fL) | 3.426259099632 |
| Lambert (L) | 3,183.098861837907 |
| Apostilb (asb) | 0.318309886184 |
When you need it
Context: SDR monitors target 80–120 nits, phones peak above 2,000 nits outdoors, and SMPTE recommends ~48 nits (14 fL) for dark-room cinema. If a projector spec says lumens, that is total flux — luminance depends on screen size and gain.
Sources & methodology
Conversion factors follow NIST Special Publication 811; exact-by-definition factors are marked in the tool itself. All math runs client-side in your browser — nothing is uploaded.
More conversion guides
- How to convert lux to foot-candles
- How to convert mcd to candela and candlepower
- How to calculate TV and monitor dimensions from the diagonal
Or browse everything at once in the new unit & sizing converters roundup.