Illuminance
phot to lux Converter
1 ph = 10,000 lx. Enter any value and the result updates instantly.
Convert
Accuracy and rounding
Illuminance measures light arriving at a surface. It is different from lumens, which describe luminous flux.
Lux is lumens per square meter; foot-candles are lumens per square foot, using the exact international foot.
Whole lux values are usually enough for room surveys; calibrated lighting work should follow the meter resolution.
How to convert phot to lux
- Type the phot value in the calculator.
- Keep phot selected as the from unit and lux selected as the to unit.
- Use the instant result, or copy it with the copy button.
phot to lux chart
| phot | lux |
|---|---|
| 1 ph | 10,000 lx |
| 2 ph | 20,000 lx |
| 5 ph | 50,000 lx |
| 10 ph | 100,000 lx |
| 25 ph | 250,000 lx |
| 50 ph | 500,000 lx |
| 100 ph | 1,000,000 lx |
Formula
lx = ph x 10,000
Example: 1 ph = 10,000 lx.
Source
Illuminance factors from NIST light-unit conversion tables, using lux as the shared reference unit.
Common questions
How do I convert phot to lux?
Enter the phot value in the converter, or multiply by the factor shown in the formula. 1 ph = 10,000 lx.
What should I watch out for?
Lux and foot-candles measure light on a surface, not total lamp output in lumens.
Where does this illuminance conversion come from?
Illuminance factors from NIST light-unit conversion tables, using lux as the shared reference unit. ConverterBase uses stable definitions and fixed conversion factors, not live or rounded market data.