Lux to Watts Calculator
Estimate the electrical power needed to reach a specific lux level over a given area.
P(W) = [E_v(lx) × A(m²)] / η(lm/W)
500 lx over 20 m² with LED (90 lm/W) = (500 * 20) / 90 ≈ 111.1 Watts
How do I convert lux to watts?
Lux measures light on a surface, while watts measure electrical power. To convert between them, you need the surface area and the luminous efficacy of the light source. Formula: Watts = (Lux × Area) / Luminous Efficacy.
What is luminous efficacy?
Luminous efficacy is a measure of how well a light source produces visible light. It is expressed in lumens per watt (lm/W). LEDs have higher efficacy than incandescent bulbs.
What area should I use?
The area is the surface over which the light is distributed. For a standard room or office calculation, this is usually measured in square meters (m²).
🔗 Related Calculators
📐 Formula
P(W) = [E_v(lx) × A(m²)] / η(lm/W)
📝 Example Calculation
500 lx over 20 m² with LED (90 lm/W) = (500 * 20) / 90 ≈ 111.1 Watts
❓ Frequently Asked Questions
How do I convert lux to watts?▼
Lux measures light on a surface, while watts measure electrical power. To convert between them, you need the surface area and the luminous efficacy of the light source. Formula: Watts = (Lux × Area) / Luminous Efficacy.
What is luminous efficacy?▼
Luminous efficacy is a measure of how well a light source produces visible light. It is expressed in lumens per watt (lm/W). LEDs have higher efficacy than incandescent bulbs.
What area should I use?▼
The area is the surface over which the light is distributed. For a standard room or office calculation, this is usually measured in square meters (m²).