Luminance Converter
Instantly convert Luminance between SI and common engineering units including cd/m², Nit, cd/cm², cd/ft². No formula lookup required.
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About
Fundamentals
Luminance is a basic physical quantity for measuring the relevant object; unit conversion unifies dimensions across standards, drawings and test data.
This tool uses cd/m² as the base unit and scales the input by each unit's factor to the target; temperature and similar quantities use affine conversion $y=a x+b$. All factors are relative to SI.
History
Measurement of Luminance has a long history: ancient standards used body parts (cubit, foot) or nature (sundials, water clocks); the metric system (1790s) and SI (1960) unified global measurement.
Engineering applications
In mechanical design, trade, international drawings and test data, Luminance must often be converted between customary units such as cd/m² and SI to keep dimensions consistent.
Glossary
| Base unit | Reference unit, usually SI (e.g. cd/m²). |
| Conversion factor | Proportional factor between a unit and the base. |
| Linear / affine | Most units are linear; temperature needs an offset (affine). |
How to use
- Enter the value to convert in the Value box.
- Pick the source and target units from the From / To dropdowns.
- Click Convert; the result shows below. Use ⇅ to swap units.
Formula · Worked Example · Knowledge
Formula
Worked Example
Key Points
- Covers 7 common units with bidirectional conversion and unit swap.
- Engineering-significant figures; scientific notation for extreme values.
- Unifies dimensions across standards, test data and reports.
Parameters
Supported units
| Unit | Base factor |
|---|---|
| cd/m² | |
| Nit | |
| cd/cm² | |
| cd/ft² | |
| Stilb | |
| Apostilb | |
| Lambert |
Applications
- Unified unit conversion in science/eng.
- Teaching and dimensional checks
- Standardising reported data