Unit Conversion

Convert numbers between two units quickly and precisely

Luminance

Unit Conversion

Convert luminance: candela per square meter, stilb, and lambert

Luminance states how bright a luminous or reflecting surface appears and is stated in candela per square meter (cd/m², colloquially nit). In the older CGS system, stilb (sb) and lambert (L) are common; in the US, foot-lambert (fL); and in parts of Europe, apostilb (asb).

Key conversion factors:

  • 1 stilb (sb) = 10,000 candela per square meter
  • 1 lambert (L) ≈ 3,183 candela per square meter
  • 1 foot-lambert (fL) ≈ 3.426 candela per square meter
  • 1 candela per square meter ≈ 314.16 apostilb (asb) – or 1 asb ≈ 0.00318 cd/m²

Applications:

  • Display technology: stating screen brightness in candela per square meter
  • Traffic engineering: luminance of traffic signs and displays

The luminance converter supports comparing display brightness and photometric specs.

Frequently asked questions about converting luminance

"Nit" is a colloquial term for candela per square meter (cd/m²), the standard unit for display brightness. A typical smartphone display reaches about 500 to 1,000 nits, with HDR-capable devices sometimes reaching significantly more.

1 stilb (sb) equals 10,000 candela per square meter (cd/m²). Stilb comes from the older CGS system of units and is barely used actively today, but occasionally appears in older physics texts.

Illuminance (lux) describes how much light falls on a surface. Luminance (cd/m²), on the other hand, describes how bright that surface actually appears to an observer – i.e. the light emitted or reflected by the surface. For illuminance, use the illuminance converter.