Illuminance Converter
Convert between 9 illuminance units instantly. Enter a value, pick your units and get the result with the formula, a full conversion table and worked examples.
50 fc in all illuminance units
Updates live as you type. Click a row to set it as the target unit.
| Unit | Symbol | Value |
|---|---|---|
| Nox | nx | 538,196 |
| Millilux | mlx | 538,196 |
| Lux | lx | 538.196 |
| Lumen per sq metre | lm/m² | 538.196 |
| Foot candle | fc | 50 |
| Lumen per sq foot | lm/ft² | 50 |
| Kilolux | klx | 0.538196 |
| Phot | ph | 0.0538196 |
| Lumen per sq centimetre | lm/cm² | 0.0538196 |
How to Convert Illuminance Units
Illuminance is the luminous flux falling on a surface per unit area. The SI unit is the lux (lx = 1 lm/m²); lighting design in the US uses foot candles, where 1 fc ≈ 10.764 lx.
Every unit on this page is stored as a fixed factor relative to one reference unit, the lux (lx). Converting is a two step multiply and divide:
- Multiply your value by the factor of the source unit to get the value in lx.
- Divide that result by the factor of the target unit.
Foot candle to Lux conversion table
| Foot candle (fc) | Lux (lx) |
|---|---|
| 1 fc | 10.7639 lx |
| 2 fc | 21.5278 lx |
| 3 fc | 32.2917 lx |
| 4 fc | 43.0556 lx |
| 5 fc | 53.8196 lx |
| 6 fc | 64.5835 lx |
| 7 fc | 75.3474 lx |
| 8 fc | 86.1113 lx |
| 9 fc | 96.8752 lx |
| 10 fc | 107.639 lx |
| 15 fc | 161.459 lx |
| 20 fc | 215.278 lx |
| 25 fc | 269.098 lx |
| 30 fc | 322.917 lx |
| 40 fc | 430.556 lx |
| 50 fc | 538.196 lx |
| 75 fc | 807.293 lx |
| 100 fc | 1,076.39 lx |
| 250 fc | 2,690.98 lx |
| 500 fc | 5,381.96 lx |
| 1,000 fc | 10,763.9 lx |
Illuminance Units and Conversion Factors
Value of one unit expressed in lx.
| Unit | Symbol | In lx |
|---|---|---|
| Nox | nx | 0.001 |
| Millilux | mlx | 0.001 |
| Lux | lx | 1 |
| Lumen per sq metre | lm/m² | 1 |
| Foot candle | fc | 10.76391042 |
| Lumen per sq foot | lm/ft² | 10.76391042 |
| Kilolux | klx | 1,000 |
| Phot | ph | 10,000 |
| Lumen per sq centimetre | lm/cm² | 10,000 |
Frequently Asked Questions
What is the SI unit of illuminance?
The SI unit of illuminance is the lux (lx). Illuminance is the luminous flux falling on a surface per unit area.
How do I convert fc to lx?
To convert foot candle (fc) to lux (lx), multiply the value in fc by 10.7639. For example, 1 fc = 10.7639 lx.
How do I convert lx to fc?
To convert lux (lx) to foot candle (fc), multiply the value in lx by 0.092903. For example, 1 lx = 0.092903 fc.
How do I convert ph to lx?
To convert phot (ph) to lux (lx), multiply the value in ph by 10,000. For example, 1 ph = 10,000 lx.
Can I see a value in every illuminance unit at once?
Yes. Enter a value and choose the source unit; the "all units" table below the converter instantly lists the equivalent in all 9 supported units. Click any row to make it the target unit.
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