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Illuminance converters

4 converters. Lux, foot-candles and phots, each with the formula and the math worked out with your numbers.

Illuminance

Lux to foot-candles lx → fc 500 lx = 46.45 fc Foot-candles to lux fc → lx 50 fc = 538.2 lx Phots to lux ph → lx 1 ph = 10,000 lx Lux to kilolux lx → klx 50,000 lx = 50 klx

Illuminance units at a glance

Unit Symbol In lux Defined as
Lux lx 1 1 lm/m²
Foot-candle fc 10.76391 1 lm/ft²
Phot ph 10,000 1 lm/cm² (CGS)
Kilolux klx 1,000 1,000 lx

Typical light: an office is 300–500 lx, an overcast day about 1,000 lx, and direct sunlight up to 100,000 lx.