Illuminance
lux to phot Converter
1 lx = 0.0001 ph. Enter any value and the result updates instantly.
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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 phot values are usually enough for room surveys; calibrated lighting work should follow the meter resolution.
How to convert lux to phot
- Type the lux value in the calculator.
- Keep lux selected as the from unit and phot selected as the to unit.
- Use the instant result, or copy it with the copy button.
lux to phot chart
| lux | phot |
|---|---|
| 1 lx | 0.0001 ph |
| 10 lx | 0.001 ph |
| 100 lx | 0.01 ph |
| 1,000 lx | 0.1 ph |
| 10,000 lx | 1 ph |
| 100,000 lx | 10 ph |
Formula
ph = lx x 0.0001
Example: 1 lx = 0.0001 ph.
Source
Illuminance factors from NIST light-unit conversion tables, using lux as the shared reference unit.
Common questions
How do I convert lux to phot?
Enter the lux value in the converter, or multiply by the factor shown in the formula. 1 lx = 0.0001 ph.
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.