Lighting

Lux to Watts Calculation — ChiefEngineer.in

Worked step-by-step example. Estimate power from illuminance, area and luminous efficacy. Open interactive calculator →

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Result

Power
50 W

Formula

P = E × A / ηv

Variables

  • E — illuminance (lx)
  • A — area (m²)
  • ηv — efficacy (lm/W)

Worked Example

Input: 500 lx, 10 m², 100 lm/W

Result: P = 50 W

Assumptions & Notes

Uniform-illumination estimate. Real lighting design requires luminaire photometry and maintenance factors.

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