Illuminance Converter
Illuminance measures how much light falls on a surface. The SI unit is the lux, one lumen per square meter. Lighting design in the US uses foot-candles, one lumen per square foot. For reference, a bright office is around 500 lux and direct sunlight exceeds 100,000 lux.
13 units supported Base unit lux (lx)
Multiply the number of lux by 0.09290304 to get foot-candles. How this is calculated
About illuminance conversion
Illuminance conversion is commonly needed when lighting design, workplace compliance, and photography. A bright office is around 500 lux, while direct sunlight exceeds 100,000 lux — over two hundred times more.
Popular conversions
Convert Lux to other illuminance units
1 lx expressed in every other illuminance unit on this site.
- Lux lx 1
- Kilolux klx 0.001
- Millilux mlx 1,000
- Lumen per Square Meter lm/m² 1
- Lumen per Square Centimeter lm/cm² 0.0001
- Lumen per Square Foot lm/ft² 0.09290304
- Foot-candle fc 0.09290304
- Phot ph 0.0001
- Nox nx 1,000
- Meter-candle m·cd 1
- Centimeter-candle cm·cd 0.0001
- Flame flame 0.02322576
- Watt per cm² (at 555 nm) W/cm² (555 nm) 1.4641288e-7
Complete list of illuminance units
All 13 units this converter supports, each stated against the lux (lx).
| Unit | Symbol | System | In lux | Conversions |
|---|---|---|---|---|
| Lux | lx | SI | base unit (lx) | lux to foot-candles |
| Kilolux | klx | SI | 1 klx = 1,000 lx | — |
| Millilux | mlx | SI | 1 mlx = 0.001 lx | — |
| Lumen per Square Meter | lm/m² | SI | 1 lm/m² = 1 lx | — |
| Lumen per Square Centimeter | lm/cm² | Metric | 1 lm/cm² = 10,000 lx | — |
| Lumen per Square Foot | lm/ft² | Imperial | 1 lm/ft² = 10.7639104167 lx | — |
| Foot-candle | fc | Imperial | 1 fc = 10.7639104167 lx | foot-candles to lux |
| Phot | ph | Metric | 1 ph = 10,000 lx | — |
| Nox | nx | Other | 1 nx = 0.001 lx | — |
| Meter-candle | m·cd | Metric | 1 m·cd = 1 lx | — |
| Centimeter-candle | cm·cd | Metric | 1 cm·cd = 10,000 lx | — |
| Flame | flame | Other | 1 flame = 43.0556416668 lx | — |
| Watt per cm² (at 555 nm) | W/cm² (555 nm) | Other | 1 W/cm² (555 nm) = 6,830,000 lx | — |
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Frequently asked questions
What is the base unit for illuminance?
Illuminance conversions on this site are calculated against the lux (lx).
Which illuminance units can I convert?
You can convert between 13 units, including lux, kilolux, millilux, lumen per square meter, and more.
Where is illuminance conversion useful?
It is commonly needed when lighting design, workplace compliance, and photography.
Does this converter mix measurement systems?
The converter supports SI, Metric, Imperial, Other units and keeps their exact definitions separate so results stay accurate.
Related categories
Conversion factors are based on internationally agreed unit definitions. See our methodology and sources for details on how these values are verified.