Lumens to Watts Calculator
Convert light brightness (lumens) into electrical power consumption (watts).
P(W) = Φ_v(lm) / η(lm/W)
800 lumens with LED (90 lm/W) = 800 / 90 ≈ 8.89 Watts
How do I convert lumens to watts?
To convert lumens to watts, divide the luminous flux (lumens) by the luminous efficacy (lumens per watt) of the light source. Formula: Watts = Lumens / Luminous Efficacy.
Why does the conversion depend on the bulb type?
Different bulbs produce different amounts of light for the same power. For example, an LED might produce 90 lumens per watt, while an old incandescent bulb might only produce 15 lumens per watt.
What is a typical efficacy for LED bulbs?
Modern consumer LED bulbs typically range from 70 to 110 lumens per watt (lm/W). High-efficiency industrial LEDs can exceed 150 lm/W.
🔗 Related Calculators
📐 Formula
P(W) = Φ_v(lm) / η(lm/W)
📝 Example Calculation
800 lumens with LED (90 lm/W) = 800 / 90 ≈ 8.89 Watts
❓ Frequently Asked Questions
How do I convert lumens to watts?▼
To convert lumens to watts, divide the luminous flux (lumens) by the luminous efficacy (lumens per watt) of the light source. Formula: Watts = Lumens / Luminous Efficacy.
Why does the conversion depend on the bulb type?▼
Different bulbs produce different amounts of light for the same power. For example, an LED might produce 90 lumens per watt, while an old incandescent bulb might only produce 15 lumens per watt.
What is a typical efficacy for LED bulbs?▼
Modern consumer LED bulbs typically range from 70 to 110 lumens per watt (lm/W). High-efficiency industrial LEDs can exceed 150 lm/W.