What size generator do I need?

How generator sizing works

Generators have two ratings: running (rated) watts for continuous load, and starting (surge) watts for the extra jolt motors need to spin up. Add the running watts of everything you’ll run at once, then add the single largest starting surge on top — a fridge or well pump can briefly draw 2–3× its running watts. Your generator’s starting-watt rating must clear that peak, or it’ll stall.