Christmas lights usually come in different sizes and wattages, depending on their intended use. Generally, Christmas lights can range anywhere from 10 watts to 300 watts, although some specialty lights may have even higher wattages. The wattage determines how much electricity the lights use and how bright they are. If you're looking to brighten up your home with Christmas lights, be sure to check the wattage rating of the lights you purchase to ensure they are suitable for your needs.