# Watts to Lumens Calculator

Converting electric power measured in watts to luminous flux measured in lumens can be a straightforward process with the right steps and tools.

Calculating luminous flux involves knowing the power consumption and the luminous efficacy of a light source.

To determine the luminous output, one can use a calculator that accepts input for power in watts and luminous efficacy in lumens per watt.

By simply inputting these values, the calculator provides the luminous flux result in lumens.

These values usually represent typical or average efficacy for various light sources, allowing users to obtain practical and useful results.

## Convert Watts to Lumens

To determine lumens from watts, multiply the power in watts (P) by luminous efficacy (η).

Luminous efficacy measures how efficiently a light source converts power into visible light. Higher values indicate more light output per unit of power.

This formula can help choose energy-efficient lighting:

[ \text{Luminous Flux } (\text{lm}) = \text{Power } (\text{W}) \times \text{Luminous Efficacy } (\text{lm/W}) ]

## Changing Watts to Lumens

To find lumens using watts, multiply the power in watts by the luminous efficiency in lumens per watt.

This calculation gives the luminous flux, ΦV, in lumens. The formula is:

**ΦV = P × η**

Where **P** is power in watts and **η** is luminous efficacy in lumens per watt.

For example, a 60-watt lamp with a luminous efficacy of 15 lumens per watt produces:

ΦV = 60 W × 15 lm/W = 900 lm

### Efficiency Values Chart

Here is a simple chart showing common luminous efficacy values for different light sources:

Light Source | Lumens per Watt (lm/W) |
---|---|

Incandescent Bulb | 10-17 |

CFL | 35-100 |

LED | 80-100 |

Halogen | 16-24 |

This chart helps understand how energy is converted into light across different technologies.