Phots to foot-candles
Type a value in phots to see it in foot-candles straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the phots box.
- Read the result in foot-candles as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
fc = ph × 929.0304
Multiply the value in phots by 929.0304 to get foot-candles.
Example
To convert 25 ph to foot-candles: 25 × 929.0304 = 23,225.8 fc.
Conversion table
| Phots (ph) | Foot-candles (fc) |
|---|---|
| 1 | 929.03 |
| 2 | 1,858.06 |
| 3 | 2,787.09 |
| 5 | 4,645.15 |
| 10 | 9,290.3 |
| 20 | 18,580.6 |
| 25 | 23,225.8 |
| 50 | 46,451.5 |
| 100 | 92,903 |
| 250 | 232,258 |
| 500 | 464,515 |
| 1,000 | 929,030 |
About the units
- Phot
- The CGS unit of illuminance, one lumen per square centimeter, exactly 10000 lux.
- Foot-candle
- One lumen per square foot, exactly 10.763910416709722 lux, used in US lighting specifications.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many foot-candles are in one phot?
1 ph = 929.03 fc exactly.
How do I convert phots to foot-candles?
Use fc = ph × 929.0304. For example, 25 ph = 23,225.8 fc.
How many phots are in one foot-candle?
1 fc = 0.00107639 ph.
What is the difference between lux and lumens?
Lumens are the total light a lamp emits, while lux is how much of it lands on each square meter. A 1000 lumen lamp spread over 10 square meters gives 100 lux.
Why is a foot-candle about 10.764 lux?
A square foot is exactly 0.09290304 square meters, so one lumen per square foot equals 1 / 0.09290304 lumens per square meter.