Heat pump or gas heating?

From the gas you use today to the heat your home needs: what a heat pump would cost to run at your own prices, and how long it takes to pay for itself.

It costs you more per year

$64

with a heat pump: $730 instead of $666

Gas: $666 a year
Heat pump: $730 a year
Never pays back

With 450 therms of gas a year and a furnace or boiler at 80% efficiency, your home uses about 10,551 kWh of heat. A heat pump with a SCOP of 2.5 makes that with 4,220 kWh of electricity: $730 a year instead of $666, $64 more.

At these prices, the heat pump costs more to run every year, so the price difference never pays back. Break-even: the heat pump comes out ahead as long as electricity costs less than $0.158 per kWh, or its SCOP is above 2.7.

The heat pump’s running cost, split

What you spend on gas today$66691%
Extra with the heat pump$649%

I’m not an accountant or a financial advisor. This is an estimate, for information only. Check with a professional before you decide.

Your numbers

example: change the numbers

Currency

This changes the symbol and the examples. It does not convert your numbers.

Your gas bill measures gas in

ThermsUSkWhUK, EuropeMJ1 GJ = 1,000 MJ

Gas used in a year

A full year from your bills, in the unit you picked above. Count only the gas a heat pump would replace: heating, plus hot water if it will heat your water too.

Gas price, per therm, kWh or MJ

What one unit of gas costs you, taxes included: add up the per-unit supply and delivery charges on your bill. Fixed monthly or daily charges go in their own field below.

Furnace or boiler efficiency

US: the AFUE rating. 80% is the federal minimum for most new gas furnaces made since 2015; ENERGY STAR gas furnaces are rated 95% or more. UK and Europe: the seasonal efficiency on the energy label (an A-rated boiler is 90% to 98%).

Heat pump SCOP

Seasonal coefficient of performance: units of heat per unit of electricity over a whole heating season, from the product sheet. US heat pumps are rated in HSPF2: divide it by 3.412 (HSPF2 8.5 is about 2.5). The example is only an example.

Electricity price, per kWh

What you pay per kWh, taxes included. The US, UK and euro examples are official averages; the Canadian, Australian and Swiss ones are round examples. Use your own.

Fixed gas charges you’d stop paying, per year

If you’d close your gas account, enter a year of its standing charge (UK) or customer charge (US). Leave it at 0 if you’ll keep gas for cooking or hot water, or if your gas price above already includes them.

Extra cost of the heat pump

How much more the heat pump costs you than a new furnace or boiler, installed, after rebates and grants. The example is just an example: use your own quotes. Enter 0 if it costs you no more.

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The math
	Gas used in a year	450 therms
×	Energy per unit100,000 Btu	29.3071 kWh
=	Energy in the gas	13,188 kWh
×	Furnace or boiler efficiency	80%
=	Heat your home needs	10,551 kWh
÷	Heat pump SCOP	2.5
=	Heat pump electricity	4,220 kWh
	Running cost with gas450 therms at $1.48	$666.00
	Running cost with a heat pump4,220 kWh at $0.173	$730.10
=	Extra per year	$64.10
	One kWh of heat with gas costs	$0.063
	One kWh of heat with a heat pump costs	$0.069

How it works

From gas to heat: a year of gas times its energy content gives the kWh in the gas (1 therm is 100,000 Btu, or 29.3 kWh; 1 kWh is 3.6 MJ). Multiply by the furnace or boiler efficiency, and you get the heat your home actually needs.
From heat to electricity: a heat pump delivers as many units of heat per unit of electricity as its SCOP says, so it needs the heat divided by the SCOP.
The costs: gas used times the gas price, plus the fixed charges you’d drop by closing the account; electricity times the electricity price. The payback is the extra cost divided by one year’s savings, at today’s prices.
Use an efficiency on the same basis as the gas on your bill: the AFUE rating in the US, or the seasonal efficiency on the EU and UK energy label, which counts the gas at its gross calorific value. Figures above 100% use the net calorific value and don’t fit here.

Worked example

450 therms × 29.3071 = 13,188 kWh of gas; at 80% efficiency that’s 10,551 kWh of heat. A SCOP of 2.5 needs 10,551 ÷ 2.5 = 4,220 kWh of electricity. Gas: 450 × $1.48 = $666 a year. Heat pump: 4,220 × $0.173 = $730 a year, $64 more, so it never pays back. It would break even with electricity at $0.158 per kWh, or a SCOP of 2.7.

Sources

Text checked on September 30, 2026

Good to know

It’s a snapshot at today’s prices. If gas or electricity prices move, so do the savings: the break-even line tells you how much room there is.
The US and euro examples use average prices that already spread fixed charges over each unit, so the extra kWh a heat pump uses usually cost a little less than the average. The UK example uses the price cap’s unit rates, with the gas standing charge kept separate.
The SCOP on a product sheet is a lab figure. In your home, it depends on your climate and on how hot the water in your radiators needs to be, so try a lower number too.
Maintenance isn’t included, and neither is the cooling many heat pumps also provide in summer, or the air conditioner it might replace.
Where the examples come from: for the US, EIA’s 2025 averages (gas at $15.34 per thousand cubic feet, about $1.48 a therm; electricity at 17.30¢ per kWh), and 450 therms is close to the 44.9 million Btu an average gas-heated home used for space heating in 2020; for the UK, the Ofgem price cap for October to December 2026 (gas 7.97p and electricity 26.32p per kWh, gas standing charge 29.68p a day) and Ofgem’s typical 9,500 kWh of gas a year; for the euro, Eurostat’s EU averages for the second half of 2025. The Canadian, Australian and Swiss examples are round numbers, not official averages.

Frequently asked questions

Is a heat pump cheaper to run than a gas furnace?

It depends on the gap between your electricity and gas prices, and on the SCOP. At US average prices in 2025, an 80% furnace burning 450 therms costs about $666 a year, and a heat pump with a SCOP of 2.5 about $730, so gas wins by $64. The same heat pump comes out ahead if electricity costs less than about 15.8¢ per kWh, or with a SCOP above 2.7.

What is SCOP, and how does it relate to HSPF2?

SCOP, the seasonal coefficient of performance, is how many units of heat a heat pump delivers per unit of electricity over a whole heating season. US ratings use HSPF2, measured in Btu per watt-hour: divide it by 3.412 to get the same kind of number. HSPF2 8.5 is about 2.5, and the federal minimum for new split heat pumps, HSPF2 7.5, is about 2.2.

How much electricity does a heat pump use?

The heat your home needs divided by the SCOP. In the example, the home needs about 10,551 kWh of heat, so a heat pump with a SCOP of 2.5 uses about 4,220 kWh of electricity a year.

Are there grants or tax credits for heat pumps?

In England and Wales, the Boiler Upgrade Scheme gives £7,500 toward an air source heat pump. In the US, the federal Energy Efficient Home Improvement Credit covered improvements made through December 31, 2025, so it doesn’t apply to new installs; check state and utility rebates. Put your net cost in the extra cost field.

Why does my boiler say it’s more than 100% efficient?

Some ratings use the net calorific value, which leaves out the heat recovered from condensing water vapor. The EU and UK energy label counts the gas at its gross calorific value, and on that basis a boiler stays below 100%: an A-rated one is 90% to 98%. Use that figure here, or your furnace’s AFUE rating.