Lumens to Watts Calculator

Calculating the conversion between luminous flux and electric power is essential for optimizing and understanding lighting efficiency.

Luminous flux, measured in lumens, indicates the total amount of visible light emitted by a source. By determining how effectively a light source converts electrical energy into visible light, one can measure its luminous efficacy, represented in lumens per watt.

Using a simple method, individuals can input the desired luminous flux and luminous efficacy values to determine the power, in watts, required to produce that level of brightness.

This approach helps to evaluate the performance of various light sources by analyzing their efficacy values, which are typically average numbers, and assists in making informed decisions about energy use.

Conversion from Lumens to Power in Watts

The power in watts for a light source is found by dividing its brightness, in lumens, by its efficiency, measured in lumens per watt.

This method helps compare how much power different light bulbs use. Energy-saving bulbs like LEDs and fluorescents provide more brightness with less energy used.

Lumens to Watts Reference Chart

LumensIncandescent (W)LED/Fluorescent (W)
375 lm25 W6.23 W
600 lm40 W10 W
900 lm60 W15 W
1125 lm75 W18.75 W
1500 lm100 W25 W
2250 lm150 W37.5 W
3000 lm200 W50 W

This chart shows different luminance and their power usage for traditional and energy-saving light sources.

Converting Brightness in Lumens to Power in Watts

Chart of Light Efficiency

Luminous efficacy measures how effectively a light source converts electricity into light. It is often expressed in lumens per watt (lm/W). Here’s a simple table to illustrate various light types and their usual efficacies:

Light TypeEfficacy (lm/W)
Incandescent10-17
Halogen16-24
CFL35-100
LED80-100+

Brightness to Power Table

To find out how much power in watts a light uses based on its lumens, use the equation: Watts = Lumens / (Lumens per watt). Below is an example table:

LumensEfficacy (lm/W)Watts
8001080
8002040
8001008