Generator Size Checks

Will a 6500 watt generator run refrigerator, sump pump, and router?

Use the default WattSizer rule: add running watts, then model the largest startup load while the other selected loads are already running.

Running watts1,255 W
Starting watts2,405 W
Recommended size2,900 W

A 6,500 W unit clears this estimate, subject to nameplate checks.

The peak-starting assumption is driven by 1/2 hp sump pump. With the default 20% buffer, WattSizer rounds up to the next 100 watts.

ApplianceRunningStartingSource note
Refrigerator180 W1,200 WDOE appliance-use guidance says sample wattages vary by age and features; default is a conservative planning value for a modern full-size refrigerator.
1/2 hp sump pump1,050 W2,200 WPump manufacturer nameplates and DOE reminder to verify actual labels; default covers many 1/2 hp residential sump pumps.
Router and modem25 W25 WHome electronics wattage varies by device; DOE advises measuring or checking adapters for accurate values.

Try the load yourself

Edit this scenario

Running load0 W
Starting load0 W

Recommended generator0 W
LoadRunning wattsStarting watts

Power station estimate

For battery units, the selected running load needs about 0 Wh for 8 hours or 0 Wh for 12 hours before weather, battery age, and inverter losses.

Safety check

Never operate a fuel-burning generator indoors, in a garage, on a porch, or near open windows. Use a listed transfer switch or interlock installed by a qualified electrician for home wiring, and verify actual device nameplates before buying equipment.

Generator or power station?

Fuel generators are useful for motor loads and longer outages, while battery power stations are better for indoor-safe electronics and medical-device planning. For battery sizing, this selected running load is about 12,050 Wh for 8 hours with the same buffer.

Never operate a fuel-burning generator indoors, in a garage, on a porch, or near open windows. Use a listed transfer switch or interlock installed by a qualified electrician for home wiring, and verify actual device nameplates before buying equipment.