Contents
- 1 🔥 Heat Pump Sizing & Fuel Savings Calculator
- 1.1 1Home & climate parameters
- 1.2 2Your current heating fuel
- 1.3 3Heat pump efficiency & electricity rate
- 1.4 ✓Recommended system & savings
- 1.5 📊Compare every fuel (with your settings)
- 1.6 📤Save & share
- 1.7 Heat pump sizing chart by climate & home size
- 1.8 How heat pumps save money (COP explained)
- 1.9 Heat pump vs gas furnace vs propane vs oil vs electric
- 1.10 Climate zone reference (US / Canada / UK)
- 1.11 Step-by-step: how to use this calculator
- 1.12 Heat pump sizing & savings FAQ
🔥 Heat Pump Sizing & Fuel Savings Calculator
Find the heat pump tonnage your home needs (heating + cooling load from area, climate, and insulation) and estimate annual fuel savings compared to your current Natural Gas, Propane, Heating Oil, or Electric Resistance system. Built on ACCA Manual J residential heating-load figures and real-world COP (Coefficient of Performance) values.
1Home & climate parameters
These determine your home’s heating load and the recommended heat pump tonnage. Sized using ACCA Manual J factors for an 8-ft ceiling home.
2Your current heating fuel
Pick your current fuel and the rate your utility charges. The annual bill is optional: leave it blank to use the modeled estimate from your home size and climate above, or enter your real 12-month total to calibrate the estimate to your actual home. Defaults are US national averages.
3Heat pump efficiency & electricity rate
Cold-climate heat pumps maintain high COP down to -15°C / 5°F and qualify for higher rebates (IRA 25C, Canada GREA). Standard inverter heat pumps are cheaper upfront but lose efficiency below 0°C / 32°F.
✓Recommended system & savings
📊Compare every fuel (with your settings)
Same home, same climate, same heating load — but using the default rate for each fuel. Best row = lowest annual heat-pump bill after switching from that fuel.
| Current fuel | Default rate | Annual HP bill | Net savings |
|---|---|---|---|
| Natural Gas Furnace | $1.20 / therm | — | — |
| Propane (LPG) | $3.50 / gallon | — | — |
| Heating Oil | $4.50 / gallon | — | — |
| Electric Resistance | $0.15 / kWh | — | — |
Heat pump sizing chart by climate & home size
Sizing a heat pump starts with your home’s heating load — the BTUs per hour your home loses in the coldest hour of the year. That’s a function of three things: home size (square footage of conditioned area), climate zone (how cold it gets), and insulation quality. For a standard 8-ft ceiling home in average insulation:
| Home Size | Mild Climate (Tons) | Moderate Climate (Tons) | Cold Climate (Tons) |
|---|---|---|---|
| 1,000 – 1,400 sq ft | 2.0 Ton (24k BTU) | 2.5 Ton (30k BTU) | 3.0 Ton (36k BTU) |
| 1,400 – 1,800 sq ft | 2.5 Ton (30k BTU) | 3.0 Ton (36k BTU) | 3.5 Ton (42k BTU) |
| 1,800 – 2,200 sq ft | 3.0 Ton (36k BTU) | 3.5 Ton (42k BTU) | 4.0 Ton (48k BTU) |
| 2,200 – 2,800 sq ft | 3.5 Ton (42k BTU) | 4.0 Ton (48k BTU) | 5.0 Ton (60k BTU) |
| 2,800 – 3,600 sq ft | 4.0 Ton (48k BTU) | 5.0 Ton (60k BTU) | 5.5 Ton (66k BTU) |
| 3,600 – 4,000 sq ft | 5.0 Ton (60k BTU) | 5.5 Ton (66k BTU) | 6.0 Ton (72k BTU)* |
* Beyond 5.0 tons, most residential heat pumps use two outdoor units in parallel, or step up to light-commercial equipment. The calculator caps at 60,000 BTU for residential class.
How heat pumps save money (COP explained)
A traditional furnace or boiler creates heat by combusting fuel — burning natural gas, propane, or oil. The combustion process loses energy to the flue: typical AFUE efficiencies are 80–85% for older furnaces and 95–98% for condensing models. So even the best furnace is at best 98% efficient.
A heat pump doesn’t create heat at all — it transfers existing heat from outside air into your home. For every 1 kWh of electricity it consumes, it can deliver 2.5 to 4+ kWh of heat (depending on outdoor temperature). The ratio of heat output to electrical input is called the COP — Coefficient of Performance:
- Standard inverter heat pump: COP 3.0–3.4 at 47°F (i.e. 300–340% efficient)
- Cold-climate inverter heat pump: COP 3.5–4.0 at 47°F, COP 2.5+ at 5°F (still highly efficient below freezing)
That’s why heat pumps are significantly cheaper to run than any combustion-based system in regions where electricity is reasonably priced. The only fuels that beat a heat pump on operating cost today are free fuels: solar thermal, geothermal (ground-source), or off-peak / time-of-use electricity.
Heat pump vs gas furnace vs propane vs oil vs electric
The fuel comparison table above shows what your heat pump bill would be if your home currently used each of the four major fuels. The math uses default fuel rates for each system and your selected electricity tariff. The order from “best switching savings” to “worst” generally comes out as:
- Electric Resistance → Heat Pump: biggest savings (often 50–65%). Electric baseboards are essentially 100% efficient but the heat pump delivers the same heat at 1/3 the kWh.
- Propane → Heat Pump: large savings (often 30–50%). Propane rates ($3.50+/gal in most US regions) make combustion expensive.
- Heating Oil → Heat Pump: similar to propane (often 30–45% savings), provided electricity tariffs stay normal.
- Natural Gas → Heat Pump: smaller but still meaningful savings (often 20–35%) in regions where gas is cheap ($1.00–$1.30/therm). In regions with high gas prices or carbon surcharges ($2.00+/therm), savings jump to 40%+.
The 5-year cumulative number in the results panel assumes electricity and fuel rates stay flat over 5 years — that’s the simple payback assumption. Real-world cumulative savings depend on rate inflation (electricity often rises faster than gas), climate trends, and equipment maintenance costs.
Climate zone reference (US / Canada / UK)
Use this map to pick the right climate tier for your ZIP code or region:
| Tier | Typical regions | Design heating load |
|---|---|---|
| Mild / Sunbelt | Florida, Gulf Coast TX, Southern California, Phoenix AZ, Mediterranean EU | 20–30 BTU/sqft |
| Moderate / Mid-US | Mid-Atlantic (DC, VA, MD), Tennessee, Kansas, Oklahoma, UK, Northern Italy | 30–45 BTU/sqft |
| Cold / Northern | Northeast US (NY, MA, PA, ME), Upper Midwest (MN, WI), Canada, Scotland, Scandinavia | 40–60+ BTU/sqft |
In cold climates, always choose a cold-climate heat pump with COP ≥ 3.5 at 5°F. Standard inverter units lose capacity rapidly below 30°F and may need electric-resistance backup strips — which kills the savings.
Step-by-step: how to use this calculator
- Enter your home area using the slider (500–4,000 sq ft) or type the exact value.
- Pick your climate zone based on the table above. When in doubt, choose Moderate.
- Pick your insulation quality: Poor (older home, single-pane windows), Average (default — 1990s–2010s build), or Well-Insulated (new build or post-retrofit).
- The calculator shows your recommended heat pump tonnage.
- Pick your current heating fuel and enter your typical annual heating bill.
- Enter the fuel rate you actually pay (default US averages: $1.20/therm gas, $3.50/gal propane, $4.50/gal oil, $0.15/kWh electric).
- Pick your heat-pump efficiency tier: Standard inverter (COP 3.0) or Cold-Climate (COP 3.8).
- Pick your currency (USD, INR, AED, SAR, EUR, GBP, AUD) and enter your electricity rate.
- Read the results: heat pump tonnage, annual bill, net savings, 5-year cumulative.
- Scroll down to the fuel comparison table to see how your savings change if you were on a different fuel.
- Download a PDF report or email the summary to your installer.
Heat pump sizing & savings FAQ
What size heat pump do I need for a 2,000 sq ft home?
For a 2,000 sq ft home in a moderate climate with average insulation, the typical sizing is 3.0–3.5 Tons (36k–42k BTU/hr). In a hot Sunbelt climate with good insulation, 2.5 Tons (30k BTU) may be enough. In a cold Northern climate with poor insulation, size up to 4.0–5.0 Tons (48k–60k BTU). This calculator gives you a specific answer based on your inputs.
Are heat pumps really cheaper to run than gas furnaces?
Yes, in most regions. A heat pump with COP 3.0 delivers 3 units of heat per 1 unit of electricity, while a gas furnace at 85% AFUE delivers 0.85 units of heat per unit of gas. Even after converting BTU to kWh at your local utility prices, heat pumps win in regions where residential gas exceeds ~$1.30/therm or electricity is under $0.20/kWh. In regions with very cheap gas (e.g. $0.80/therm) and expensive electricity ($0.25+/kWh), the gap narrows but heat pumps still usually win.
Can a heat pump replace both my furnace and AC?
Yes — that’s the most common residential heat-pump installation. A heat pump provides both heating (by extracting heat from outside air) and cooling (by reversing the cycle and dumping heat outside). A single ducted or ductless heat-pump system can replace a gas furnace + central AC in most climates, eliminating the need for two separate systems.
What is HSPF2 and why does it matter?
HSPF2 (Heating Seasonal Performance Factor 2) is the North American efficiency rating for heat-pump heating, similar to miles-per-gallon for a car. HSPF2 ÷ 3.412 ≈ COP. A standard inverter unit has HSPF2 around 8.5 (COP 2.5–3.0); a high-efficiency cold-climate unit has HSPF2 of 10+ (COP 3.5–4.0). Always check HSPF2 — not the older HSPF — when comparing models.
How accurate is this fuel-savings estimate?
It uses a back-calculated approach: your stated annual heating bill is converted to kWh of delivered heat (factoring in your current system’s efficiency), then divided by the heat pump’s COP and multiplied by your electricity rate. This is accurate to within ±15% in most cases. For an exact figure, request a utility-bill analysis from your HVAC contractor — they’ll normalize for weather (HDD / CDD) and confirm your home’s actual heating energy.