What size generator to run a house?

Check, uncheck or adjust the typical device list below — watts, startup surge and battery size update instantly. Numbers come from U.S. DOE, ENERGY STAR and manufacturer spec sheets, not marketing copy.

1. Check what you need to power

Refrigeration & Freezers

  • 1
  • 1

Kitchen

  • 1
  • 1

Heating, Cooling & Fans

  • 1

Water & Pumps

  • 1

Laundry & Cleaning

  • 1
  • 1

Electronics & Office

  • 2
  • 1

Medical Devices

Power Tools & Outdoor

Lighting

  • 12

2. Your sizing

Running load11,863 Wtypical range 453–534 W depending on your specific models
Startup peak26,113 Wdriven by 1× Central AC (3-ton, 36,000 BTU)
Daily energy39,870 Wh
Recommended capacity49,840 Whincludes 25% margin for inverter loss & battery depth of discharge

3. Best cross-brand matches

No single portable power station covers this load — look at expandable systems (e.g., EcoFlow DELTA Pro 3 + extra battery, Anker SOLIX F3800 expansion packs) or a fixed home battery instead.

Static answer (crawlable summary)

Typical device list: Refrigerator (side-by-side, ~24 cu ft)×1, Freezer (upright, ~15 cu ft)×1, Central AC (3-ton, 36,000 BTU)×1, Furnace Fan (1/2 HP blower)×1, Submersible Well Pump (1/2 HP, 240V)×1, Clothes Washer×1, Clothes Dryer (gas)×1, Dishwasher (with heated dry)×1, Microwave Oven×1, Electric Kettle×1, Router + Modem×1, LED Bulb (60W equivalent)×12, TV (65-inch LED)×1, Laptop Computer×2, Phone / Smartphone Charger×4.

Continuous load11,863 W
Startup peak26,113 W (driven by 1× Central AC (3-ton, 36,000 BTU))
Daily energy use39,870 Wh
Recommended capacity49,840 Wh (25% margin included)
Minimum inverter13,050 W continuous

Frequently asked questions

What size generator to run a house?

For a typical setup (refrigerator (side-by-side, ~24 cu ft), freezer (upright, ~15 cu ft), central ac (3-ton, 36,000 btu), furnace fan (1/2 hp blower) and submersible well pump (1/2 hp, 240v)), you need at least 11,863W of continuous power. The single biggest moment is startup: when 1× central ac (3-ton, 36,000 btu) kicks on, the momentary draw peaks at 26,113W. For overnight runtime we recommend at least 49,840Wh of battery capacity (your devices use about 39,870Wh per day, plus a 25% margin).

Which power stations can handle this?

Look for a station whose surge rating covers 26,113W and whose capacity is at least 49,840Wh.

Why is the startup surge higher than the running watts?

Motor-driven devices (fridge compressors, well pumps, air conditioners) draw 2-5× their running power for a split second at startup — measured as locked-rotor amps (LRA). A generator that only meets the running load will trip or stall when the biggest motor starts. Our data sources: U.S. DOE Energy Saver, ENERGY STAR certified product database, and manufacturer spec sheets (Franklin Electric, Goodman, Zoeller).

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