Luminance Converter

About the luminance converter

Luminance measures how much light a surface emits or reflects toward an observer per unit area, and is the quantity your eye actually perceives as brightness. Display engineers, photographers, and lighting designers all work in luminance because it predicts perceived contrast far better than raw lumens. The SI unit is the candela per square meter (cd/m²), which is identical to the nit used by display manufacturers; older optics literature uses stilb (cgs) and the imperial foot-lambert. Use this converter to translate between the units quoted on TV spec sheets, photometer readings, and traditional optical references.

Frequently asked questions

• Is 1 nit the same as 1 cd/m²? +

  Yes — the nit is just a more compact name for the candela per square meter. A 500-nit display and a 500 cd/m² display are identically bright.

• How bright is a typical screen in cd/m²? +

  Office monitors run around 250–350 cd/m². Mobile phones often peak at 800–2,000 cd/m² for HDR highlights, and direct sunlight reflecting off white paper is roughly 30,000 cd/m².

• What is a foot-lambert and where is it used? +

  A foot-lambert is the imperial unit for luminance and equals about 3.426 cd/m². It is still used in cinema projection standards (e.g. SMPTE recommends ~14 fL for theatrical screens).