How to Convert Light Output from an Incandescent to a Compact Fluorescent

When you are replacing an incandescent light bulb with a compact fluorescent there is an easy way to make sure you are getting close to the same amount of light. You can either multiply the CFL wattage by 4 or divide the wattage by 4 on the incandescent and you will be close to the same light output.

13 to 15 watt CFL = 60 watt incandescent
18 to 20 watt CFL = 75 watt incandescent
23 to 27 watt CFL = 100 watt incandescent
38 to 42 watt CFL = 150 watt incandescent

Beyond using this formula to insure that you are purchasing a compact fluorescent with enough light, is to compare lumens from the bulbs you were using to the one you are looking to purchase. Light is not measured in wattage but measured in lumens. The above is a rule of thumb. The lumens are king.

Holly Eddins

If my table lamp says use now more than a 60 watt bulb, can I use a lower watt flourescent bulb that puts out lumens of a 100 watt bulb?

That's a great question. As long as your table lamp is not enclosed you should be fine. You are referring to a 23 or 27 watt cfl that would be equivalent to a 100 watt incandescent bulb.

There are two factors to consider, one is the draw of energy that the table lamp is made to take. This is no problem since the wattage you'll be using is so much less. The second is the heat generated. CFLs still generate a fair amount of heat in their ballasts but as long as the fixture you are using it in isn't enclosed, you should be fine. Unfortunately, there is no hard and fast rule.

Holly Eddins