Illuminance Converter

Convert lux, foot-candles and phot.

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Remember only the selected units in this browser. Numbers and other inputs are not saved. Used for fresh standalone examples; shared links and workspace cards keep their own choices.

Your numbers

Converted value

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Conversion factors are defined relative to the displayed base unit. Input precision limits meaningful output precision; this does not change a physical quantity or perform a safety assessment.

Formula

y = x × a ÷ b

x is the input, y is the converted value, a is the source-unit factor and b is the target-unit factor. Use the factors in the table below.

Unit conversion factors

Base unit: lx

Unit	Base units per listed unit
Lux	1
Foot-candles	10.7639104167
Phot	10,000

Convert lux, foot-candles and phot.

Worked example

Value to convert: 1
From unit: Foot-candles
To unit: Lux

Converted value: 10.7639104167 lx
Value in base unit: 10.7639104167 lx

Scope and limitations

Conversion factors are defined relative to the displayed base unit. Input precision limits meaningful output precision; this does not change a physical quantity or perform a safety assessment.

Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.

Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.

Formula version: 66f2a7bef664 · Example checked: 2026-10-30

Methodology