Unit converter

Illumination converter

Convert illuminance units including lux, foot-candles, phot, and nox.

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1 lx = 1 m·cd

All Illumination units

From 1 lx
UnitValue
Lux lx 1
Meter-candela m·cd 1
Centimeter-candela cm·cd 0.0001
Foot-candela ft·cd 0.09290304
Phot ph 0.0001
Nox nox 1,000
Lumen/square meter lm/m² 1
Lumen/square centimeter lm/cm² 0.0001
Lumen/square foot lm/ft² 0.09290304
Watt/square centimeter (at 555 nm) W/cm² 0.0000000015
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Common tasks

Reference

How illumination conversion works

Illuminance measures luminous flux incident on a unit area. Values are normalized to Lux before conversion to the requested output unit.

Values are converted to lux first, then from that reference into the requested unit. Keeping a single documented reference reduces inconsistent pair-by-pair constants.

Accuracy note: SI relationships follow the cited reference. Conventional and domain-specific factors use the established ConvertWin factor inventory; verify safety-critical work against the governing standard.

Unit reference

UnitSymbol1 unit in lx
Luxlx1
Meter-candelam·cd1
Centimeter-candelacm·cd10,000
Foot-candelaft·cd10.76391042
Photph10,000
Noxnox0.001
Lumen/square meterlm/m²1
Lumen/square centimeterlm/cm²10,000
Lumen/square footlm/ft²10.76391042
Watt/square centimeter (at 555 nm)W/cm²683,000,000

Long-tail directory

Every indexed conversion

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Primary source

Definitions and standards

The SI framework is checked against NIST Guide for the Use of the International System of Units. Conventional factors are retained from the extended ConvertWin inventory and carry the accuracy note shown above.

See Methods & sources for rounding rules, exact-value handling, and review policy.

Questions

Illumination FAQ

What is the reference unit for illumination conversions?

ConvertWin uses lux (lx) as the internal reference for this category, then converts to the selected output unit.

How accurate is this illumination converter?

SI relationships follow the cited reference. Conventional and domain-specific factors use the established ConvertWin factor inventory; verify safety-critical work against the governing standard.