What size power station do I need?

Add up the running watts of everything you'll run at once; your power station's continuous output must clear that. Its surge rating must clear the biggest single startup spike (motors and compressors). And its watt-hours must cover your running load for the hours you need — PowerFit computes all three from published appliance and station data and recommends the smallest unit that's enough.

How many watt-hours do I need to run a refrigerator?

A modern fridge runs ~150 W but only cycles about a third of the time, so it averages ~50 W — roughly 1,200 Wh per day. A 1,000–1,500 Wh power station keeps it cold through a typical outage. Always size the surge too: the compressor can spike to ~1,200 W on startup.

What size power station do you actually need?

Brand "sizing" tools push you up their own lineup. We don't sell hardware — we compute it. Add what you need to run, set how long, and we'll show the units that genuinely fit: enough running watts, enough surge, enough watt-hours — the smallest sufficient one first, never oversold.

Quick start — common outage kits

Your load — set a quantity for each appliance you'll run

Outage Essentials

Refrigerator (modern) 150 W · 1,200 W surge Chest Freezer 100 W · 1,000 W surge WiFi Router + Modem 20 W LED Lights (10 bulbs) 100 W Garage Door Opener (1/2 HP) 550 W · 1,100 W surge

Medical & CPAP

CPAP Machine (no humidifier) 40 W CPAP with Heated Humidifier 60 W · 95 W surge Oxygen Concentrator 350 W · 600 W surge

Heating & Cooling

Space Heater (1500 W) 1,500 W Window AC (8,000 BTU) 715 W · 1,250 W surge Window AC (12,000 BTU) 1,100 W · 1,800 W surge Gas Furnace Blower (1/2 HP) 800 W · 2,350 W surge Pellet Stove 300 W · 800 W surge Portable AC (10,000 BTU) 1,100 W · 1,800 W surge Box / Pedestal Fan 100 W · 200 W surge

Kitchen

Microwave (1000 W cooking) 1,200 W Coffee Maker 1,000 W Electric Kettle 1,500 W Toaster 850 W Slow Cooker 200 W Hot Plate (single burner) 1,200 W

Comfort & Electronics

LED TV (55") 120 W Laptop 60 W Desktop Computer 200 W · 400 W surge Phone / Tablet Charging 12 W Electric Blanket 100 W

Pumps, Tools & Off-Grid

Sump Pump (1/3 HP) 800 W · 1,500 W surge Sump Pump (1/2 HP) 1,050 W · 2,150 W surge Well Pump (1/2 HP) 1,000 W · 2,100 W surge Dehumidifier 500 W · 900 W surge Mini Fridge 100 W · 400 W surge Power Tool Charger 100 W

Hours you need to run it

⚡ Informational only — a computed sizing estimate from published appliance-wattage charts and manufacturer station specs. It is not an electrical guarantee. For hardwired or whole-home backup, transfer switches, or any permanent install, consult a licensed electrician.

Or start from a common scenario

Pre-filled, high-intent outage and off-grid scenarios — each with the full math and matched units.

Power station for a home outage (fridge + CPAP + sump pump)

12 h horizon

What size power station runs a CPAP all night?

8.0 h horizon

What size power station / battery backup for a sump pump?

6.0 h horizon

What size power station / solar generator for van life?

12 h horizon

What size power station runs a refrigerator in an outage?

24 h horizon

What size power station runs a 1500 W space heater?

3.0 h horizon

What size power station runs a window AC?

5.0 h horizon

What size power station / solar generator for an off-grid cabin?

12 h horizon

What size power station for partial-home backup?

8.0 h horizon

How sizing works (in three numbers)

Running watts. Add up everything running at once. Your unit's continuous output has to clear it.
Surge watts. Motors and compressors spike on startup. We take the worst single spike landing on top of the rest of the running load — your unit's surge rating has to clear that.
Watt-hours. Running load × hours, adjusted for the fact that fridges and pumps only cycle part of the time, ÷ a 90% usable reserve. Your unit's capacity has to cover it.

We recommend the smallest unit that clears all three, plus a step-up for headroom. Full method → · Sources: appliance wattages from standard charts; station specs from manufacturers (compiled 2026-06-15; approximate — always confirm the nameplate). Methodology →