How Many Watts to Power a House in an Outage? (2026 Calculator Guide)

The essentials, in watts

~150–800W

Fridge / freezer

The must-run load. Surges higher when the compressor kicks in, so leave headroom.

~10–100W

Lights & phones

LED lights and charging are tiny loads — a small station runs these for days.

~1,000–1,500W

Space heater / kettle

Heat and hot water are the hogs. These are what push you to a bigger generator.

2,000W+

Realistic backup

A 2,000W+ unit covers fridge, lights, phones and a small appliance — the essentials, comfortably.

The trick: don't size for your whole house — size for the handful of things you must run, and stagger the big draws. That's how a modest generator keeps you comfortable.

The DIY blueprint we reviewed

For a repairable build sized to the essentials, The clearest beginner plan we've tested is the Easy DIY Power Plan — a parts list and step-by-step build for a small working generator. Honest verdict: a great weekend build and a real skill, not a magic bill-killer. Our full breakdown:

See The Easy DIY Power Plan 60-day money-back guarantee

Read our full honest review →

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