Lifetime - hours (h)

During that lifetime, 80% of the lamps must still be working and emitting 80% of their rated luminous flux.

The light output from all light sources, LED, halogen, metal halide and fluorescent decreases over time. The amount of light from the light source at a specific time in the future is referred to as the lamp lumen maintenance factor, or LLMF. The lifetime of a lamp is defined as the time it takes until its light output, or lumen maintenance, reaches 70-80% of the initial output.

Typical Average Rated Life for Various Types of Bulbs

Incandescent 750 - 2 000 hours
Fluorescent 24 000 - 36 000 hours
HID 10 000 - 24 000 hours
Compact Fluorescent
Plug-in 10 000 - 20 000 hours
Screw-based 8 000 - 10 000 hours
Halogen 2 000 - 4 000 hours
LED 25 000 - 50 000 hours