What Size Generator Do You Need to Run a Chest Freezer?
By the Generator Size Calculator Team · Updated · 6 min read
Quick answer: Honda lists a refrigerator or freezer at about 700 running watts and 2,200 starting watts. A 3,000-watt generator runs a freezer with room to spare, and a 3,500-watt unit runs two freezers and a few lights. Many chest freezers draw less than the Honda figure, so check the label. Per the CDC, a full freezer keeps food safe for about 48 hours if the lid stays closed, so you can run the generator in short blocks.
Freezer watts
| Appliance | Running watts | Starting watts |
|---|---|---|
| Refrigerator or freezer | 700 | 2,200 |
| TV | 300 | 300 |
| Dehumidifier | 650 | 800 |
A freezer has a compressor, so it needs extra watts for a moment to start. Honda's 700 and 2,200 are typical figures. Many chest freezers, especially small or efficient ones, use less than this, and a plug-in watt meter or the label will tell you for sure. See starting vs running watts.
Which generator size to choose
| Generator | One freezer | Two freezers and lights |
|---|---|---|
| Small inverter, about 2,000 W (1,600 running, 2,000 peak) | Close call, check the label | Too tight |
| 3,000 W | Yes | Yes, with care |
| 3,500 W | Yes | Yes |
For a fridge and a freezer together, see what size generator runs a refrigerator.
Example: two freezers
| Load | Running watts |
|---|---|
| Chest freezer | 700 |
| Upright freezer | 700 |
| Running total | 1,400 |
The start-up surge adds about 1,500 watts on top (2,200 minus 700) for one compressor at a time, so the peak is about 2,900 watts. A 3,500-watt generator carries 1,400 running watts well under its 80% mark (2,800 watts), and its approximate 4,400-watt starting capacity covers the peak.
List the freezers, lights and anything else.
How long food stays frozen
The CDC says a full freezer keeps food safe for about 48 hours and a half-full freezer about 24 hours if the door or lid stays closed, with the freezer at 0°F or below. So for a short outage you may not need a generator at all, and for a longer one you can run the generator in blocks, then keep the lid shut in between. See how long a generator runs on a tank of gas.
Tips to save fuel
- Keep the lid closed except when you have to open it.
- Start the generator first, then plug in the freezers one at a time.
- Use a heavy outdoor cord. See the extension cord calculator.
- Check the temperature, with a thermometer in the freezer, before you decide food is safe.
Run the generator outdoors, at least 20 feet from doors, windows and vents. Never in a garage or shed, even with the door open. See how far a generator should be from your house.
Frequently asked questions
How many watts does a chest freezer use?
Honda lists a refrigerator or freezer at about 700 running and 2,200 starting watts. Many chest freezers use less, so check the label or measure it.
Can a 2000-watt generator run a chest freezer?
Sometimes. The 2,200-watt start-up figure is just above a typical 2,000-watt inverter's peak, but many freezers start lower. Check your label.
Can a 3500-watt generator run two freezers?
Yes. Two freezers and some lights total about 1,400 running watts and a peak near 2,900 watts.
How long can a freezer go without power?
The CDC says about 48 hours if full and 24 hours if half full, with the lid kept closed.
Do I need to run the generator all day?
Usually not. Run it for a few hours at a time and keep the lid closed in between.
Related calculators
Sources: Running and starting watts from the Honda generator wattage guide (refrigerator or freezer, television, dehumidifier); food safety times and temperatures from the U.S. Centers for Disease Control and Prevention. Generator sizes apply the 80% running rule and an assumed starting capacity about 25% above rating.