Estimate yearly, monthly and daily running costs, then compare with a gas boiler.
Default prices use the Ofgem price cap unit rates for 1 October to 31 December 2026 (direct debit). Standing charges are excluded because you pay them with or without a heat pump. Results are estimates.
Thinking about swapping your gas boiler for a heat pump, or already running one and wondering what it really costs? This free heat pump running cost calculator shows your yearly, monthly and daily cost in seconds, using the latest Ofgem price cap unit rates as a starting point. It also puts the figure side by side with a gas boiler, so you can see straight away whether a heat pump saves you money in your home.
What Is a Heat Pump Running Cost Calculator?
A heat pump running cost calculator works out how much electricity a heat pump needs to heat your home and hot water over a year, then turns that into pounds and pence. A heat pump does not create heat by burning fuel. It moves heat from the outside air or the ground into your home, so every unit of electricity it uses delivers several units of heat. That ratio is called the seasonal coefficient of performance (SCOP).
The calculator divides your home's annual heat demand by the SCOP to find the electricity used, then multiplies it by your electricity unit rate. For the gas comparison, it divides the same heat demand by your boiler's efficiency and multiplies by the gas unit rate. Standing charges are left out because you pay them whether or not you have a heat pump.
How to Use the Calculator
Step 1: Choose Your Home Type
Pick the option closest to your home, from a small flat to a large detached house. This fills in a typical annual heat demand for you. If your Energy Performance Certificate (EPC) lists a figure for space heating and hot water, choose Enter my own figure and type it in for a more accurate result.
Step 2: Set the Heat Pump Efficiency (SCOP)
Enter the SCOP from your heat pump's datasheet or installer quote. Most modern air source heat pumps in UK homes reach between 2.8 and 4. Ground source systems usually sit between 3.5 and 4.5. If you are not sure, leave the default of 3.2.
Step 3: Check Your Energy Prices
The electricity and gas boxes start with the current price cap unit rates. Replace them with the rates on your latest bill, or with a dedicated heat pump tariff rate if you are on one. To see how your whole household bill changes, including standing charges, try the energy bill calculator with the same rates. Cheaper electricity makes a big difference to the final figure.
Step 4: Read and Compare Your Results
The results panel updates as you type. You will see the yearly cost, the average per month and per day, a typical winter month, and what a gas boiler would cost for the same heat. If you also want to cut the electricity bill itself, the solar panel calculator estimates how much power a roof array could supply each year. The coloured box tells you how much you could save, or how much extra you would pay, at the prices you entered.
What Affects Heat Pump Running Costs?
- Insulation: a well insulated home needs less heat, so the pump runs for fewer hours.
- Flow temperature: running radiators at 35 to 45°C keeps the SCOP high. Higher flow temperatures lower efficiency.
- Electricity tariff: time of use and heat pump tariffs can cut costs well below the price cap rate.
- Installation quality: correct sizing and set up matter as much as the brand of heat pump.
- Weather: very cold spells reduce efficiency for a short time, which is why winter months cost more.
For independent guidance on insulation and grants, the Energy Saving Trust heat pump guide is a reliable place to start.
Frequently Asked Questions
How much does it cost to run a heat pump per day?
For a typical three bedroom semi-detached home with a SCOP of 3.2, it averages around £2.70 a day across the year at current price cap rates. Daily costs are higher in winter and much lower in summer.
Is a heat pump cheaper to run than a gas boiler?
It depends on your SCOP and electricity price. With a SCOP above roughly 3 and price cap rates, running costs are similar or slightly lower. On a heat pump tariff, the saving is usually larger.
What is a good SCOP for a heat pump?
A SCOP of 3 or more is good for an air source heat pump in the UK. Anything above 3.5 is excellent and usually means low flow temperatures and a well designed system.
Why are standing charges not included?
You pay the electricity standing charge either way. If you remove gas completely, you also stop paying the gas standing charge, which adds roughly £100 a year to your saving.
How do I find my home's heat demand?
Check your EPC for the space heating and hot water figures, or add up the gas kWh on your bills for a year and multiply by your boiler efficiency.
Does the calculator work for ground source heat pumps?
Yes. Enter the SCOP of your ground source system, usually between 3.5 and 4.5, and the calculator works the same way.