Estimate what size heat pump you need based on your home's square footage, location, and condition. Results in tons, BTU/h, and installed cost range. Uses real design temperatures for Canadian and US cities — not rules of thumb. Free to use — no signup required.
See the sizing chart below for quick estimates by square footage and climate zone.
Estimated heat pump size (tons) by home size and climate severity. Assumes average insulation.
| Home Size | Mild | Moderate | Cold | Very Cold |
|---|---|---|---|---|
| 800 sq ft | 1T | 1.5T | 2T | 2.5 |
| 1,000 sq ft | 1.5T | 2T | 2.5T | 3 |
| 1,200 sq ft | 1.5T | 2T | 2.5T | 3.5 |
| 1,500 sq ft | 2T | 2.5T | 3T | 4 |
| 1,800 sq ft | 2.5T | 3T | 3.5T | 4.5 |
| 2,000 sq ft | 2.5T | 3T | 4T | 5 |
| 2,500 sq ft | 3T | 3.5T | 4.5T | 5+ |
| 3,000 sq ft | 3.5T | 4T | 5T | 5+ |
| 3,500 sq ft | 4T | 4.5T | 5T | 5+ |
| 4,000 sq ft | 4.5T | 5T | 5+T | 5+ |
A 1,800 sq ft two-storey home in Toronto, ON (design temp -20°C) built in the 1990s with average insulation needs approximately 3–3.5 tons (36,000–42,000 BTU/h). At typical installed prices of $8,500–$17,000 before rebates, the Ontario Home Renovation Savings Program and federal incentives could reduce costs by $5,000–$7,500+. In this climate, a cold-climate heat pump rated to at least -25°C is strongly recommended.
Heat pump size is measured in tons or BTU/h (1 ton = 12,000 BTU/h). The goal is to match the heat pump's capacity to your home's peak heating and cooling loads — the maximum amount of heat your home loses on the coldest design day, or gains on the hottest. Getting it right matters more for heat pumps than for furnaces, because an oversized heat pump short-cycles, wastes energy, and fails to dehumidify in summer.
The professional method uses your city's design temperature — the outdoor temperature your area stays above 97.5% of winter hours, based on 30 years of weather data. Vancouver's is -7°C; Edmonton's is -33°C. That 26-degree gap means the same house in each city needs a very different heat pump.
In Canada, the standard is CSA F280-12, used by software like Right-F280, TECA HLHG, and HOT2000. In the US, it's ACCA Manual J. Both calculate your home's actual heating and cooling loads room by room, accounting for every wall, window, and air leak. A professional load calc costs $150–$400 and is the only reliable way to size a heat pump — and it's often required for rebate eligibility in provinces like BC and Ontario.
In a cold Canadian climate with average insulation, a 1,500 sq ft home typically needs 2.5–3.5 tons (30,000–42,000 BTU/h). In a mild climate like Vancouver or Seattle, 2–2.5 tons may be enough.
Expect 3–4 tons (36,000–48,000 BTU/h) for average insulation in a cold climate. A well-insulated home might only need 2.5 tons, while a drafty older home could need 5 tons.
No. Oversizing is one of the most common and costly mistakes. An oversized system short-cycles, wastes energy, doesn't dehumidify properly, and wears out faster. Variable-speed heat pumps are somewhat more forgiving, but proper sizing still matters.
Modern cold-climate heat pumps (ccASHP) are rated to -25°C and below. They maintain useful heating output in most Canadian conditions. In very cold regions, plan for supplemental backup heating for the coldest days.
It's the outdoor temperature your location stays above for 97.5% or 99% of winter hours, based on 30 years of data. It's what engineers use to size heating systems — cold enough to handle nearly all conditions, without oversizing for the single coldest hour ever.
Central ducted systems typically cost $6,000–$18,000 installed. Ductless mini-splits run $4,000–$10,000. Provincial rebates and federal incentives can reduce costs by $5,000–$12,000+.
One ton equals 12,000 BTU/h. Residential heat pumps range from 1.5 to 5 tons. A 3-ton unit provides 36,000 BTU/h of capacity.
Planning insulation upgrades before your heat pump install? See our insulation calculator to estimate batts, rolls, and blown-in quantities.
Typical Results
💡 If your result seems too high, try 'Upgraded / retrofit' — selecting an older home age than your actual construction significantly overestimates the load.
Common Mistakes