Phot to Foot-candles Converter

Summary

This converter translates phot (ph) illuminance values into foot-candles (fc). The phot is the CGS unit of illuminance — one lumen per square centimeter — equal to 10,000 lux. Because 1 foot-candle = 10.76391041671 lux, the exact conversion factor is 1 ph = 10,000 ÷ 10.76391041671 = 929.0304 fc. All calculations run client-side in your browser. A reference table covers common lighting environments so you can put any result in practical context.

How it works

1. Enter the illuminance value in phot in the input field.
2. The converter applies the exact factor: fc = ph × 929.0304.
3. The foot-candle result appears instantly with the full formula shown.
4. Use the swap button to convert foot-candles back to phot.
5. Click any row in the reference table to load that value into the converter.

Use cases

• Convert CGS phot readings from older photometric equipment into foot-candles.
• Translate historical optical research data into foot-candles for US-based documentation.
• Cross-check illuminance values in pre-SI physics or horticulture textbooks.
• Interpret grow-light data from CGS sources in foot-candle terms for American growers.
• Verify illuminance unit conversions when reviewing legacy architectural specifications.
• Compare laboratory photometry results (in phot) with American building-code foot-candle requirements.

Frequently Asked Questions