LED chips typically consume 80% less power than a halogen of equivalent brightness.

## What are lumens?

The total light output from a light source, regardless of the direction the light travels, is specified as **lumens** (lm), where 1 lumen is defined as equivalent to the light output from 1 candle. This figure is used to describe and compare lamp brightness.

## What is efficacy?

**Efficacy** (lm/w) is the total light output in lumens per watt of power consumed. The higher the lumens per watt, the more efficient a light source is. The efficacy specification is simple to calculate. For example, a LED globe that produces 720 lumens from 10 watts has an efficacy of 72 lumens per watt (720 lumens/10 watts).

### How efficient are LED lights?

The following table shows the power consumption of a LED light is typically 80% less than a halogen of equivalent brightness:

**A Comparison of Light Types**

Power | Output | Efficacy | |

Incandecent | 60 watts | 770 lm | 13 lm/w |

Halogen | 50 watts | 750 lm | 15 lm/w |

CFL | 11 watts | 740 lm | 65 lm/w |

LED | 10 watts | 720 lm | 72 lm/w |

## What is lux?

**Lux** (lx), is defined as the level of brightness at a particular distance from the light source. 1 lux is equivalent to 1 lumen per square meter, so if you measured 800 lux at 1.5m height using a lux meter, then there is 800 lumens of light per square meter at 1.5m.