How many watts do Christmas lights use?
Ever wonder how much power you really need for all those strands of Christmas lights? A little bit of simple math can help you figure it out. To calculate wattage on a strand of lights, multiply bulb wattage by the total number of lights on the strand to get the total.
Watts is a measurement of the amount of energy used and is provided per bulb or light strand. You should be able to find it listed on the bulb itself or the UL tag if using a strand. If there is no wattage, wattage meters can be purchased for less than $20.
Size does matter; an incandescent mini light bulb will use much less wattage than a larger C9 bulb. LED bulbs use approximately 80% less wattage than an incandescent bulb.