For many years, people have estimated the brightness of a light bulb by its wattage. But wattage isn’t actually a measure of brightness, but the measurement of how much power the light bulb consumes.
LEDs are so efficient that the traditional measurement of wattage is no longer useful to estimate the brightness of an LED, so equivalent comparisons have become the method that helps us determine which product to use. For example, regular household LED lamps are sold as 40w , 60w or 75w equivalent.
The true measurement unit of luminous flux (or brightness) is the lumen (lm). Lumen measurements are an acceptable method to compare LEDs to traditional light sources.
The following chart shows a roughly estimated comparison of different kinds of light sources at a glance.
|Lumens (light output)||Incandescent/ Halogen||Metal Halide/ High Pressure Sodium (HID)||Fluorescent||LED|
We’re all familiar with common household Incandescent or Halogen lighting. High Intensity Discharge (HID) lighting includes Metal Halide and High Pressure Sodium, used most often for street lighting and parking lots. Fluorescent technology has also become a common choice for a variety of applications.
But as the chart shows, LED lighting is the most efficient choice. Most LEDs deliver 70 to 110 lumens per watt. No other practical lighting technology can compare.