Heating cost calculator: heat pump, gas, oil, LPG or wood
Estimate how much heat your home needs in a year, then see what each heating system would cost to run on today's prices, how much fuel it burns, and how long a switch would take to pay back.
Yearly running cost by system
Running costs only, and only those that change with the heating choice: unit price times the energy each system buys, plus fixed charges you could stop paying by changing the heating (such as the gas standing charge). The electricity standing charge is not counted, because you pay it anyway. Excludes servicing, repairs, grants and the cost of the system itself (except in the payback line). The table compares energy and fuel costs only. It does not check whether a system can be, or is allowed to be, installed in your home: local rules, a chimney or flue, a gas connection and whether you live in a flat all decide that.
How the heating comparison works
The calculator first needs the heat your home uses in a year. If you do not know it, it multiplies the floor area by the median gas use per square metre for homes of that age in England and Wales (DESNZ National Energy Efficiency Data), converted into heat with the efficiency of a condensing boiler. That figure includes hot water, so it is a whole-home estimate, not space heating alone.
Each system then has to buy the heat divided by its efficiency: a gas boiler at 84% buys more kWh of gas than the heat it delivers, a heat pump with a seasonal performance factor (SCOP) of about 2.8 buys roughly a third as much electricity. The energy bought is priced at the unit rate. Only costs that change with the heating choice are added: fixed charges you could stop paying by changing the heating, such as the gas standing charge (you can close the gas connection), count; the electricity standing charge does not, because you pay it anyway.
Formula
- Heat demand = floor area × kWh per m² (or your own figure)
- Energy bought = heat demand ÷ efficiency (or SCOP)
- Yearly cost = energy bought × unit price + fixed charges you could stop paying by changing the heating (e.g. the gas standing charge); the electricity standing charge is not counted, because you pay it anyway
- Payback = installation cost ÷ yearly saving
Frequently asked questions
Why is the heat pump efficiency above 100%?
A heat pump moves heat from the outside air instead of making it, so one kWh of electricity delivers two to four kWh of heat over a season. The default is the median measured in the Energy Systems Catapult field trial of real UK installations; a poorly designed system can do worse, so try a lower figure as well.
Why is the gas standing charge counted but not the electricity one?
Only costs that change with the heating choice are counted. You pay the electricity standing charge anyway, for lights and appliances, so it is left out for every system. The gas standing charge is counted because you can close the gas connection when you stop heating with gas; if you would keep gas for cooking, set it to zero.
Where do oil, LPG, pellet and log prices come from?
From the Nottingham Energy Partnership's monthly fuel price survey. Delivered fuels change price often and vary by supplier and order size, so they are marked as estimates: type in the price on your last delivery note.
Does the result include grants such as the Boiler Upgrade Scheme?
No. Enter the installation cost you would actually pay after any grant, and the payback line will use that figure.
Is my data sent anywhere?
No. Everything is calculated in your browser.
Heat pump, gas or oil: what a typical UK house would pay
The calculator opens on an ordinary British house: 85 m², built between 1965 and 1982, heated by a condensing gas boiler. For homes of that age the government’s National Energy Efficiency Data (NEED) gives a median gas use of 106.2 kWh per square metre a year in England and Wales; at the 84% efficiency of a condensing boiler that is about 89 kWh of heat per m². So the house needs roughly 7,583 kWh of heat a year, hot water included. Here is what each system costs to supply it at the prices loaded on the page.
| System | Cost a year | Energy or fuel bought |
|---|---|---|
| Air-source heat pump (SCOP 2.78) | £718 | 2,728 kWh |
| Gas boiler, condensing (84%) | £828 | 9,027 kWh |
| Gas boiler, older non-condensing (74%) | £925 | 10,247 kWh |
| Wood pellet boiler (75%) | £933 | 2,106 kg |
| Log stove (65%) | £1,063 | 2,852 kg |
| Oil boiler, condensing (84%) | £1,117 | 923 litres |
| LPG boiler, condensing (84%) | £1,729 | 1,359 litres |
| Electric heaters (100%) | £1,996 | 7,583 kWh |
Why, at today’s prices, the heat pump saves only £110
The headline says the heat pump is cheapest and that switching from the condensing boiler saves about £110 a year. It is worth seeing where that figure comes from. A kWh of gas costs 7.97p under the Ofgem price cap; through a boiler that turns 84% of it into heat, a kWh of heat costs 9.49p. A kWh of electricity costs 26.32p; through a heat pump that delivers 2.78 kWh of heat for each kWh it uses, a kWh of heat costs 9.47p. Per unit of heat, the two are almost level.
Nearly all of the £110 is therefore the gas standing charge, 29.68p a day or £108.33 a year, which you stop paying only if the gas supply is closed. If you would keep gas for a hob, set the gas standing charge to 0 and the saving drops to about £2 a year. The electricity standing charge is left out for every system, because you pay it whatever heats the home.
The result is just as sensitive to the heat pump’s efficiency. With gas standing charge counted, the heat pump breaks even with condensing gas at a SCOP of about 2.4. Type 2.5 into the heat pump field and the saving falls to £29; type 3.0 and it rises to £163. The default 2.78 is the median measured by the Energy Systems Catapult across real UK installations, so roughly half of the homes in that trial did worse. How the system is designed and the water temperature it runs at make much of the difference.
The other fuels
Replacing an older non-condensing boiler (74%) with a condensing one saves £97 a year in this example on running costs alone. Oil, LPG, pellets and logs are priced from the Nottingham Energy Partnership’s October 2026 survey of delivered fuels. These move quickly and depend on order size, so the page marks them as estimates. If you heat with oil, the fuel column is the useful one: 923 litres a year here, which you can compare with your own delivery notes. Direct electric heating is the dearest at £1,996, because every kWh of heat costs the full 26.32p.
Payback, and what is not counted
Payback is the installation cost divided by the yearly saving. At £110 a year, each £1,000 of installation cost you pay yourself takes about 9.1 years to recover, before any servicing or repairs. The calculator ignores those, the cost of a boiler you would have to replace anyway, and future price changes. The current cap runs from 1 October to 31 December 2026, and Ofgem notes that there is no VAT on electricity from 1 October 2026 to 31 March 2027, while the gas rate includes 5% VAT. When either changes, the gap between gas and a heat pump changes with it, so re-run the comparison with your new rates.
Use your own figures
The NEED figure is a median for a whole age band, so your house could need a good deal more or less. Your annual statement is a better start. It shows your gas use in kWh (converted from the cubic metres on the meter). Multiply that by 0.84 if you have a condensing boiler, choose “I know my yearly heat use” and type in the result. It will include cooking if you cook on gas, which is usually a small part. Take the unit rate and standing charge from the same statement, and for oil or LPG the price per litre from your last delivery.
If you are considering a heat pump in England or Wales, the government’s Boiler Upgrade Scheme page offers a grant towards the cost of a heat pump or biomass boiler. Check the amount and conditions on that page, and enter the installation cost you would actually pay after any grant.
Sources: DESNZ NEED gas use per m², Ofgem price cap rates, Nottingham Energy Partnership fuel prices, Energy Systems Catapult heat pump trial and BRE SAP 10.2 efficiencies.