Brightness is a term used to describe light output, and the output is measured in lumens. Wattage is the measure of electrical power that is used to produce the brightness or lumens.
Finding the Lumens.
When you look at a light bulb package of a manufacturer, it gives you the wattage as well as the lumens of the bulb. The U.S. Federal Government set light bulb standards in 2007 that have been phased in over several years to require manufacturers to increase the lumens/brightness of screw based light bulbs while decreasing the wattage/electrical power.
To save energy, a homeowner should look for bulbs with the highest lumens, and then choose the one with the lowest wattage. Homeowners can also look for ENERGY STAR certified bulbs that are the same as the standard bulb you are replacing. To be Energy Star certified, a product must go through rigorous testing with third-party EPA-recognized laboratories.
According to the Energy Independence and Security Act of 2007, we can compare light bulbs this way:
- The standard 60 watt incandescent light bulb provides 13 to 14 lumens per watt.
- An equivalent CFL provides between 55 and 70 lumens per watt.
- An equivalent LED can range between 60 and 100 lumens per watt.
The color of the emitted light also affects how bright a light appears, even if the lumens are the same. Bulbs that produce light closer to the color of daylight may appear brighter because the color of the light is less yellow than other bulbs.