Luminance Converter

Convert photometric luminance units

Luminance describes how bright a surface appears per unit area, distinct from illuminance (light falling on a surface). Display engineers work in nits (candela per square meter), while US cinema specs still reference foot-lamberts. CGS texts use stilb and lambert; apostilb appears in European photometry tables.

Enter a value, choose source and target units, and read the converted result plus a reference table for every supported unit. Conversions normalize through candela per square meter using standard photometric definitions (including π factors for lambert and apostilb).

Related: Illuminance Converter, Lux to Foot-Candle Calculator.