Product links inspected October 4, 2026. Availability varies by size, seller and location.
Research review by the Worth Buying Canada team · Independent product-research team
OWNERSHIP GUIDE • CANADA · GENERATOR SIZING GUIDE • CANADA · How the evidence was assessed
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What Size Generator Do I Need?
Size a generator for the equipment that must run together—not the size of the house. Record running demand, starting demand and voltage for each essential load before choosing a wattage range.
Example generators by size class
Honda EU2200iTC
2,200 max / 1,800 rated watts
Champion 201319
3,500 W gasoline running
Generac GP3300i
3,300 starting watts; inverter generator with COsense
Westinghouse WGen9500TFc
9,500 W gasoline running · 120/240V
The simple method
- List every appliance or circuit you want powered.
- Find the actual running watts or volts × amps on the nameplate/manual.
- Add the running watts for loads that will operate together.
- Identify motors/compressors and their starting or surge requirement.
- Add the largest realistic starting surge to the continuous total.
- Choose a generator with operating margin instead of planning at 100% capacity.
- Confirm whether any essential load needs 240V.
Illustrative planning ranges
These are only rough planning ranges. Your appliance nameplate/manual is the source that matters because equipment varies significantly.
| Item | Typical planning concern | What to verify |
| Item Refrigerator/freezer. | Typical planning concern Moderate running draw with compressor start surge. | What to verify Nameplate amps and starting behaviour. |
| Item Gas-furnace blower. | Typical planning concern Usually hundreds of watts, but motor start matters. | What to verify 120V or other requirement; blower nameplate. |
| Item Sump pump. | Typical planning concern Often a large short starting surge. | What to verify Horsepower, running amps and locked-rotor/start data if available. |
| Item Well pump. | Typical planning concern Can be one of the largest loads; often 240V. | What to verify Pump voltage, horsepower and starting amps. |
| Item Microwave. | Typical planning concern High short-duration running load. | What to verify Input watts, not only advertised cooking output. |
| Item Kettle / toaster / space heater. | Typical planning concern High resistive load with little start surge. | What to verify Rated watts. |
| Item Internet / TV / laptops / LED lights. | Typical planning concern Generally small individual loads. | What to verify Add them together; use inverter power if sensitive electronics are a priority. |
2,000–2,500W class
This is a portable-load category rather than a whole-home recommendation. The Honda EU2200iTC example supplies 1,800 rated watts; whether that covers a refrigerator and other devices depends on their actual running and starting requirements. Do not assume a generic appliance combination will fit.
3,000–4,500W class
The models in this group do not have identical running capacity. Champion 201319 supplies 3,500 running watts on gasoline and 3,150 on propane; Generac GP3300i supplies 2,500 running watts. Compare those ratings—not the larger starting-watt labels—with the loads you will use together.
9,500W class
The Westinghouse WGen9500TFc example provides 9,500 gasoline running watts and 120/240V output. Those specifications broaden the possible load plan, but they do not establish that it can power every circuit in a particular home. Have the installation and load calculations assessed before purchasing.
Starting watts vs running watts
The large number printed on a generator is often the short-duration starting/peak output. Size your plan around running watts first. Then ensure there is enough extra capacity for the largest motor or compressor that may start while the other intended loads are running.
Do you need 240V?
Check this before shopping. A 4,500W 120V-only generator cannot power a 240V load simply because its wattage looks large enough. Well pumps, electric water heaters, central air conditioners and other equipment may require 240V.
Home wiring requires a proper transfer method
If the generator will energize home circuits rather than individual extension-cord loads, use properly sized, approved transfer equipment installed by qualified personnel. This isolates generator power from the utility and avoids dangerous backfeed.
CO reminder: wattage has nothing to do with safe placement. Fuel-burning generators stay outdoors; Health Canada recommends at least 6 m (20 ft) from buildings.
Compare models: Generator Comparison Database Canada.
See the ranked buying guide: Best Generators in Canada (2026).