The equivalent of a 13-watt compact fluorescent (CFL) light bulb is between 40 and 60 watts of power from an incandescent light bulb, which corresponds to between 450 and 800 lumens. Additionally, a 6- to 8-watt LED light corresponds to a 13- to 15-watt CFL bulb.
A CFL bulb uses much less energy than an incandescent bulb because very little of the electricity used to excite the mercury atoms inside is wasted as heat. In the traditional incandescent lightbulb, up to 90 percent of the electricity is wasted as heat, which explains the much higher power usage to obtain a similar output of light. An LED uses the least energy of the three options.