Convert Phots to Foot-candles (ph to fc)
1 phot (ph) = 929.0304 foot-candles (fc). 1 fc = 0.001076391042 ph. Example: 15 ph = 15 × 929.0304 = 13935.456 fc.
Also searched as phots to fc, phots in fc, phots into foot-candles, ph to fc, ph in foot-candles, ph into foot-candle, phot to foot-candle, ph to foot-candles converter and how many foot-candles in a phot.
1 ph = 929.0304 fc
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk phot to foot-candle converter to paste a column from Excel.
How to Convert Phot to Foot-candle
- 1 ph = 929.0304 fc
- 1 fc = 0.001076391042 ph
- Example: convert 15 ph to fc: 15 ph = 15 × 929.0304 fc = 13935.456 fc
Formula
fc = ph × 929.0304
Derivation from SI units:
- 1 ph = 1 lm/cm² = 10⁴ lx.
- 1 fc = 1 lm/ft² = 1/0.09290304 lx ≈ 10.7639 lx.
- 1 ph = 10000 lx ÷ 10.76391041671 lx per fc = 929.0304 fc
Both units are defined exactly, so the factor is exact. Phot definition: phot; Foot-candle definition: foot-candle.
Worked examples
- A reading of 2 ph converts to 1858.0608 fc.
2 ph × 929.0304 = 1858.0608 fc - A value of 20 ph is 18580.608 fc.
20 ph × 929.0304 = 18580.608 fc
Phot to Foot-candle conversion table
| Phots (ph) | Foot-candles (fc) |
|---|---|
| 0.1 ph | 92.90304 fc |
| 0.5 ph | 464.5152 fc |
| 1 ph | 929.0304 fc |
| 2 ph | 1858.0608 fc |
| 5 ph | 4645.152 fc |
| 10 ph | 9290.304 fc |
| 20 ph | 18580.608 fc |
| 50 ph | 46451.52 fc |
| 100 ph | 92903.04 fc |
| 1000 ph | 929030.4 fc |
Where it's used
Phots are used for older optics literature, while foot-candles appear in US lighting design (IES recommendations). Both measure illuminance (light falling on a surface), so the conversion is a fixed factor.
Phot to other illuminance units
| Conversion | 1 ph equals |
|---|---|
| phot to foot-candle | 929.0304 fc |
| phot to lux | 10000 lx |
| phot to kilolux | 10 klx |
| phot to millilux | 10000000 mlx |
Frequently asked questions
How many foot-candles are in 1 phot?
1 ph = 929.0304 fc.
How do I convert phots to foot-candles?
Multiply the value in ph by 929.0304. For example, 15 ph × 929.0304 = 13935.456 fc.
Is the ph to fc conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "phot".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "footcandle".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Phots to Foot-candles (ph to fc). Retrieved October 25, 2026, from https://scientificconverters.com/illuminance/phots-to-foot-candles/
IEEE
Scientific Converters, "Convert Phots to Foot-candles (ph to fc)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/illuminance/phots-to-foot-candles/