Running watts refer to the amount of power a device needs to function. Devices like light bulbs and coffee makers, for example, use the same amount of power to start up and continue to run—so you only have to worry about running watts in their cases. Some devices, called reactive loads, have electric motors that require additional power to start up and then less to simply stay running. Refrigerators, air conditioners, and power tools are examples of reactive loads. If you want to power reactive loads, you’ll need to factor in starting watts to how much total power you need from your generator. The amount of starting watts a generator has is the maximum watts it can produce.