Backup generator size calculator
Work out roughly how many watts of backup generator you need based on your home size and how much you want to keep running during an outage.
This is an estimate of continuous watts needed; an electrician will size the exact generator based on your appliances and HVAC.
Compare actual quotes for this projectActual sizing depends on your specific appliances, HVAC tonnage, and starting wattage, confirmed by a load calculation.
Enquiries submitted through our forms may be passed to partner providers who can do the work, and we may receive a referral fee. Our rankings and scores are based solely on our published method and are not influenced by referral fees.
Get quotes from generator installation electricians
Ranked by our published rubric from recent Google reviews, weighted by relevance to this service (the same order as the category page).
JCD ElectricGet a quote5.0(149) 92
Super Fast ElectricGet a quote4.9(679) 91
All Electric ServicesGet a quote4.9(1589) 91
American Air, Plumbing, and ElectricalGet a quote4.9(10283) 89
Quantum Force Electric LLCGet a quote5.0(150) 88