Luminance Converter
Free Luminance Converter for other units. Enter a value to see equivalent measurements across systems. Free to use with no signup required.
Formula
Converted Luminance = Value x (From Factor / To Factor)
Each luminance unit has a conversion factor to candela per square meter (cd/m2) as the base unit. One nit equals one cd/m2. One foot-lambert equals 3.42626 cd/m2. One stilb (cd/cm2) equals 10,000 cd/m2. One lambert equals approximately 3183.1 cd/m2. The apostilb relates to the lambert by a factor of pi.
Worked Examples
Example 1: Converting Display Brightness to Foot-Lamberts
Problem: A monitor has a brightness of 500 cd/m2 (nits). Convert to foot-lamberts.
Solution: cd/m2 = 500 (same as nits)\nFoot-lamberts = 500 / 3.42626 = 145.95 fL
Result: 500 nits = 145.95 foot-lamberts
Example 2: Converting Stilb to Nits
Problem: Convert 0.05 stilb (cd/cm2) to nits (cd/m2).
Solution: cd/m2 = stilb x 10,000\ncd/m2 = 0.05 x 10,000 = 500 nits\nFoot-lamberts = 500 / 3.42626 = 145.95 fL
Result: 0.05 stilb = 500 nits
Frequently Asked Questions
What is luminance and how does it differ from illuminance?
Luminance measures the brightness of a surface as perceived by the human eye, expressed in candela per square meter (cd/m2 or nits). It describes the light emitted or reflected from a surface in a given direction. Illuminance, measured in lux, describes the amount of light falling onto a surface. Think of luminance as how bright something looks and illuminance as how much light hits it. A white wall and a black wall under the same illuminance have different luminance because they reflect different amounts of light.
What luminance levels correspond to real-world scenarios?
Clear sky luminance is approximately 8000 cd/m2. Direct sunlight on white paper reaches about 30,000 cd/m2. A candle flame is roughly 7000 cd/m2. The full moon surface has a luminance of about 2500 cd/m2 as seen from Earth. A typical office computer monitor set to comfortable brightness is 120-200 cd/m2. Street lighting produces about 1-2 cd/m2 on road surfaces. The human eye can perceive luminance ranging from about 0.000001 cd/m2 (starlight) to over 100,000 cd/m2 (sunlit snow).
What formula does Luminance Converter use?
The formula used is described in the Formula section on this page. It is based on widely accepted standards in the relevant field. If you need a specific reference or citation, the References section provides links to authoritative sources.
Can I use Luminance Converter on a mobile device?
Yes. All calculators on NovaCalculator are fully responsive and work on smartphones, tablets, and desktops. The layout adapts automatically to your screen size.
Can I share or bookmark my calculation?
You can bookmark the calculator page in your browser. Many calculators also display a shareable result summary you can copy. The page URL stays the same so returning to it will bring you back to the same tool.
Is Luminance Converter free to use?
Yes, completely free with no sign-up required. All calculators on NovaCalculator are free to use without registration, subscription, or payment.