How Many Watts Do You Need to Run a Fridge, TV, and Wi-Fi During a Power Outage?
Suncis is reader-supported. If you buy through links on this page, we may earn a small commission at no extra cost to you. As an Amazon Associate, Suncis earns from qualifying purchases. Learn more.
Before you buy a power station or generator, you need one answer: how much power do I actually need? Buy too small and your fridge shuts off at 2 a.m. Buy too big and you waste hundreds of dollars.
Good news: the math is simple. This guide shows you how, step by step.
Watts vs watt-hours (in plain English)
- Watts (W) = how much power a device uses right now.
- Watt-hours (Wh) = how much energy it uses over time. Watts × hours = watt-hours.
Example: a 10-watt LED bulb on for 5 hours uses 10 × 5 = 50Wh.
How many watts common devices use
| Device | Typical running watts | Notes |
|---|---|---|
| Refrigerator | 100–250W | Uses about 1–2kWh per day. Needs 2–3× more power for a moment when the motor starts. |
| Wi-Fi router + modem | 10–20W | Small, but you want it on 24 hours. |
| Phone charging | 5–20W | Per phone. |
| Laptop | 40–100W | |
| LED light bulb | 8–12W | Per bulb. |
| TV (LED, 50″) | 60–150W | |
| CPAP machine | 30–60W | Higher with the humidifier on. |
| Microwave | 1,000–1,500W | Only runs a few minutes, but needs high output. |
| Coffee maker | 800–1,200W | |
| Window AC | 500–1,500W | Uses a lot of energy over time. |
| Space heater | 1,500W | Drains batteries very fast. |
These are typical ranges. For an exact number, check the label on the back of your device. It lists watts (W), or volts × amps (V × A = W). Or plug the device into a Kill A Watt meter, which shows the real watts while it runs.
Example: an outage day for a typical family
| Device | Watts | Hours | Watt-hours |
|---|---|---|---|
| Refrigerator | About 1,200Wh per day | 24 | 1,200Wh |
| Wi-Fi router | 15W | 24 | 360Wh |
| TV | 100W | 4 | 400Wh |
| 4 LED bulbs | 40W total | 5 | 200Wh |
| 3 phones | 15W each | 2 | 90Wh |
| Total | About 2,250Wh |
So to get through one full day, this family needs about 2,250Wh of battery.
Add a safety margin
Power stations lose about 10–15% of their energy when converting battery power to wall power. So divide your total by 0.85:
2,250Wh ÷ 0.85 ≈ 2,650Wh
That means a 2,000Wh station gets you through most of a day, and a 3,000Wh+ station covers a full day with room to spare. If you only need to get through a few evening hours, a 1,000Wh unit is enough.
Don’t forget the output (watts)
Capacity is how long. Output is how much at once. Add up everything you might run at the same time, plus the fridge’s start-up surge. For most homes, a station with 1,500–2,000W output handles a fridge plus small devices. If you want to use a microwave or coffee maker too, look for 2,000W or more.
Quick sizing cheat sheet
| What you want to run | Battery size to look for |
|---|---|
| Phones, Wi-Fi, a few lights for a night | 300–500Wh |
| Fridge + Wi-Fi + phones for half a day | About 1,000Wh |
| Fridge + Wi-Fi + TV + lights for a full day | 2,000–3,000Wh |
| Several days, or heavy appliances | 3,000Wh+ with solar panels or extra batteries |
Ready to choose? See our picks: Best Portable Power Stations for Home Backup (2026).
