Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Foot-candles to Phot
Convert fc to ph instantly, then review the formula, assumptions, and rounding guidance.
Light & sound unitsInstant result
Decimals
Formula result = input × 10.7639104167 ÷ 10000. 1 fc = 0.0011 ph
Common examples
One value, several units
Lux10.7639 lx
Phot0.0011 ph
Nox10,763.9104 nx
Conversion table
| fc | ph |
|---|---|
| 1 fc | 0.0011 ph |
| 2 fc | 0.0022 ph |
| 5 fc | 0.0054 ph |
| 10 fc | 0.0108 ph |
| 25 fc | 0.0269 ph |
| 50 fc | 0.0538 ph |
| 100 fc | 0.1076 ph |
Conversion chart
1 fc0.0011 ph
5 fc0.0054 ph
10 fc0.0108 ph
25 fc0.0269 ph
50 fc0.0538 ph
Worked example
1 foot-candle equals approximately 10.7639 lux.
Unit definition
Foot-candles (fc) One foot-candles equals 10.7639104167 lux.
Unit history
Foot-candles is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert fc to lux.
3. Convert the base value to ph and apply your display precision.
Understand the result before using it
Foot-candles to Phot converts a value measured in Foot-candles (fc) into the equivalent value in Phot (ph). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 10.7639104167 ÷ 10000
Assumptions
- Foot-candles and Phot represent the same illuminance quantity.
- The input is expressed in fc; the output is expressed in ph.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 fc = 0.00107639104167 ph. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a fc measurement in a document that expects ph.
- Compare a foot-candles value with a value reported in phot.
- Check the fc-to-ph arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Decibel sound-pressure level is logarithmic and depends on the stated reference pressure.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Foot-candles to Phot?
result = input × 10.7639104167 ÷ 10000 Using the displayed relationship, 1 fc equals 0.00107639104167 ph.
How many Phot are in one Foot-candles?
One Foot-candles is 0.00107639104167 Phot. The displayed digits may be rounded.
Can I reverse the fc to ph conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts ph back to fc.
Is the Foot-candles to Phot result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.