What do all these lighting words mean?

Kelvin, lumens, watts, oh my! Newer bulbs have a Lighting Facts label that will give you all of the details of a particular bulb (similar to a nutrition label on food). For example, we've previously looked to watts to learn a bulb's brightness; that information is now presented in lumens. See our Guide to Reading Lighting Facts for more.

Lighting Facts Per Bulb


870 lumens Brightness
Estimated Yearly Energy Cost $1.57

Based on 3 hrs/day. 11¢/kWh
Cost depends on rates and use


Energy Star Life
5.5 years

Based on 3 hrs/day


Light Appearance
Marker 2700 K
Warm Cool
       
       

13 watts Energy Used

Contains Mercury
For more on clean up and safe disposal, visit epa.gov/cfl.

Click or tap arrows for more info.

Brightness: This is measured in lumens on the label. For example, 1100 lumens has brightness equivalent to a 75-watt bulb.
Estimated Yearly Cost: This is based on a set rate of usage each day. While your actual use may vary, the dollar amount noted will give you a good baseline.
Life: The overall expected life of the bulb, often in years. This is also based on estimated daily usage.
Light Appearance: Also known as color temperature, this indicates the quality of light, ranging from warm/yellow light to cool/blue light. (Warmer light in the 2700K range is way you'd expect from a standard incandescent.) The K stands for kelvin.
Energy Used: Here is wattage in its proper place. And with a shift to more energy efficient light sources, you will not see the 40, 60, 75 or 100 watts like you used to. These days, you will more often see values in the twenties, teens or even single digits.
*Contains Mercury: Because so many fluorescent bulbs contain low levels of mercury, these bulbs outline how to properly dispose of the CFL bulb at the end of its life.

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