What size generator to run a space heater?

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

Kitchen

Heating, Cooling & Fans

  • 1
  • 1

Water & Pumps

Laundry & Cleaning

Electronics & Office

Medical Devices

Power Tools & Outdoor

Lighting

  • 2

2. Your sizing

Running load1,618 W
Startup peak1,618 Wdriven by 1× Portable Space Heater
Daily energy6,890 Wh
Recommended capacity8,620 WhBasis: 1 day of typical usage, incl. 25% margin for inverter loss & battery depth of discharge
Backup duration:

Assumptions: daily hours per device follow DOE / ENERGY STAR duty cycles; capacity adds a 25% margin. Check your appliance nameplates — actual draw varies by model.

3. Best matches from our 6-brand database

  1. EcoFlow DELTA 3 Max Plusexpandable system~$1,149
    • rated 3,000W covers your 1,780W continuous load
    • surge 6,000W covers your 1,618W start peak
    • base 2,048Wh + expansion batteries (up to 10,000Wh) covers your 8,620Wh need
    Check price →
  2. EcoFlow DELTA Pro 3expandable system~$2,799
    • rated 4,000W covers your 1,780W continuous load
    • surge 8,000W covers your 1,618W start peak
    • base 4,096Wh + expansion batteries (up to 12,288Wh) covers your 8,620Wh need
    • 120/240V split-phase output
    Check price →
  3. Jackery Explorer 2000 Plusexpandable system~$2,599
    • rated 3,000W covers your 1,780W continuous load
    • surge 6,000W covers your 1,618W start peak
    • base 2,043Wh + expansion batteries (up to 24,000Wh) covers your 8,620Wh need
    Check price →

Static answer (crawlable summary)

Typical device list: Portable Space Heater×1, Electric Blanket (double)×1, LED Bulb (60W equivalent)×2.

Estimated from: VT Extension table (DOE-derived) · Energy Star Certified Products (bulbs)

Continuous load1,618 W
Startup peak1,618 W (driven by 1× Portable Space Heater)
Daily energy use6,890 Wh
Recommended capacity8,620 Wh (25% margin included)
Minimum inverter1,780 W continuous

Frequently asked questions

What size generator to run a space heater?

For a typical setup (Portable Space Heater, Electric Blanket (double) and LED Bulb (60W equivalent)), you need at least 1,618W of continuous power. The single biggest moment is startup: when 1× portable space heater kicks on, the momentary draw peaks at 1,618W. For a full day of runtime we recommend at least 8,620Wh of battery capacity (your devices use about 6,890Wh per day, plus a 25% margin for a full day of use).

Which power stations can handle this?

Based on published specs, EcoFlow DELTA 3 Max Plus (with expansion batteries), EcoFlow DELTA Pro 3 (with expansion batteries), Jackery Explorer 2000 Plus (with expansion batteries) cover the 1,618W startup peak and deliver up to 1.5 days fully expanded / up to 1.8 days fully expanded / up to 3.5 days fully expanded of typical daily use. Check the comparison cards above for the full numbers.

Do any of these devices need extra startup power?

No — this selection (e.g. heaters, electronics, lighting) has no motor-driven devices, so the startup peak equals the running load (1,618W). Any station rated for the continuous load handles it. Note: if you add a fridge, pump or A/C unit in the calculator, its locked-rotor start (2-5× running power) will raise the peak. Data sources: U.S. DOE Energy Saver, ENERGY STAR certified products, manufacturer spec sheets.

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