What Size Generator Do I Need? (Calculator Included)

Whether you are getting a generator for backup power, camping, or powering tools at a job site, it’s important to figure out the size of generator you need. Getting a generator with insufficient power can lead to tripping its circuit breaker and potentially destroying the generator altogether.

Appliances that contain motors and compressors typically need extra power boosts during its runtime. Think of an air conditioner that needs a basic amount of power to keep the fan running but occasionally draws extra power when its compressor turns on.

Generators are rated with running watts and peak watts to show the constant and peak power that they can provide. Make sure both numbers are well within your requirement.

To calculate the size of generator you need, use the running watt and additional watt calculator tool below. The appliance wattage table below serves as an estimate. Appliance power consumption varies depending on energy efficiency. For accuracy, please refer to model specific energy labels. Contact your manufacturer if this information isn’t printed on the appliance.