Luminance Converter

About This Tool

This Luminance Converter is a tool for professionals in lighting design, display technology, and photometry. It converts units of luminance, which measures the luminous intensity per unit area of light traveling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls within a given solid angle. The base unit is candela per square meter (cd/m²).

Essentially, luminance is a measure of how bright a surface appears to the human eye from a particular angle. It is critical for specifying the brightness of displays (monitors, TVs, phones), evaluating lighting conditions, and in astronomy.

Tips & Features

• Nits and cd/m²: The candela per square meter (cd/m²) is the SI unit for luminance. An informal, but very common, name for this unit is the nit. They are exactly the same thing: 1 nit = 1 cd/m².
• Luminance vs. Illuminance: Luminance is the light emitted from a surface (brightness), while illuminance (measured in lux) is the light falling onto a surface. A white wall and a black wall in the same room have the same illuminance, but the white wall has a much higher luminance.
• Foot-Lambert (fL): This is a common unit for luminance in the U.S. film and cinema industry to describe the brightness of a movie screen.