How much does it cost to run an electric heater? I’ve done the maths so you don’t have to

Feeling the chill this winter? Then you might want to consider investing in an electric, portable heater for your home. In general, heaters aren’t too expensive to buy but after the initial purchase, there are the running costs that you need to consider – so how much does it actually cost?

Aside from keeping yourself toasty warm, there are many benefits to having a heater in your house. Compared to your central heating and boiler, heaters are more cost-effective and can help reduce your energy bills which tend to skyrocket during the colder months of the year.

If you’re considering buying a heater but are unsure how much you’ll actually be paying to run it, I did the maths so you don’t have to.

Heater running costs: how much is it and how to work it out

To figure out how much your heater costs to run, you’ll first want to check the energy price cap. As explained on Ofgem, the energy price cap is the maximum amount energy suppliers can charge you for each unit of energy used.

From 1st January - 31st December 2025, the cost of energy or electricity per kWh is 26.35p. kWh stands for kilowatt-hour which is a unit of energy that measures the amount of electricity used. This cost is going up in 2026 to 27.69p per kWh, so the running cost of your heater will increase next year.

Next, check the wattage of your heater which explains how much energy it uses to generate heat. From there, you can use the following formula to work out the running costs of your heater: kW x hours x pence per kWh.

As an example, let’s take a 2kW heater and say you’re using it for an hour. To make things easier, let’s round the 26.35p down to 26p. So, this would be 2 x 1 x 26 which totals to 52, which means it’ll cost you approximately 52p to run a 2kW heater for an hour.

In comparison to your central heating system, most boilers use between 20 - 40 kWh. As you can see from these numbers, turning on your heating is significantly more expensive than using a portable, electric heater.

If you want to save more money running a heater, there are a few tweaks you can do to keep costs down and ensure your heater is safe and stays in top condition for years to come. First, make sure you’re using the right sized heater for the right sized room – if the room is too big for the heater, this will cause your heater to work harder and waste more energy.

Next, consider where you’ve placed your heater as if it’s hiding behind furniture, it won’t be as effective and you could cause a fire. There are many other things you can do, so make sure to check out these 7 mistakes everyone makes with heaters for more details.