Watts to Lux Calculator
Convert power (watts), area and efficacy to illuminance (lux).
Input Data
Input Power P.
W
Input Area A.
m²
Input Luminous efficacy η.
lm/W
Results
100lx
E = P × η / A = 10 W × 100 lm/W / 10 m² = 100.000000 lx
At a glance:Watts to Lux Calculator: enter parameters to compute results; complements related calculators.
Formula
E = P × η / A
P: power (W), η: luminous efficacy (lm/W), A: area (m²)
How to Use
- Enter power P (watts).
- Enter area A (m²).
- Enter luminous efficacy η (lm/W).
- Get illuminance E (lux).
Case Studies
P = 10 W, A = 10 m², η = 100 lm/W
E = 10 × 100 / 10 = 100 lx.
FAQ
Vs lux-to-watts?
It is the inverse: E = P·η/A.
Larger area?
Same power over larger area → lower illuminance.
Related Tools
References
Content review: Calculatorism Science Team. Formula and numeric tests verified; results for reference only.