Top 5 Things to Know When Buying a Light Bulb

Posted on: December 7, 2012

Purchasing a light bulb can be a real task given all of the options on the market today.  Understanding a few things about light bulbs can simplify the process.

1.      They are no longer called “light bulbs”.  “Light bulb” tends to refer only to incandescent or pear-shaped bulbs.  In many stores, the term used to reference all types of “bulbs” is “lamps”.

2.      When replacing an incandescent bulb with another kind of lamp (CFL, halogen, or LED), the watts will be different.  For example, if you are replacing a 60-watt bulb with a CFL, the CFL may be 13-15 watts.  Most packaging will provide information such as “60W Replacement”.


Incandescent Bulb (Watts)


Energy Star Qualified Bulbs (Watts)



9 to 13



13 to 15



18 to 25



23 to 30



30 to 52

3.      You are shopping for lumens, not watts.  When shopping for incandescent bulbs, you shopped for watts.  Now you need to shop for lumens – a measure of light output.  Most lighting packaging will provide you with the information you need.

4.      The color of the white light is measured on a Kelvin scale.  Lower numbers (2600-3200K) means the light appears more yellow and warm.  Higher numbers mean the light is more white or blue.


5.     BE AWARE:  If your fixture is dimmable, in a three-way socket, on an electronic control (motion sensor, etc.), ore exterior to your home you need to bulbs that are labeled for that purpose!  Also pay attention to how the average life was calculated for that product.  If it assumes that you leave the light on for three hours at a time but you only use the lamp for 15 minutes at a time, you will most likely not achieve the average life indicated on the product.