How Much Does It Cost to Run a Gas Fire 2023? [Numbers Crunched]

There’s a chill in the air and you’ve got the urge to flick on the gas fire for a bit of instant heat.

But at what price?

This has been my train of thought recently after moving into a house with two gas fires!

Temperatures have dropped to single digits and less outside (30-40oF) it’s feeling pretty cold indoors too.

If I’m going to turn it on I want to know how much it costs to run a gas fire.

Let’s get straight to it.

How much does it cost to run a gas fire?

After running the calculations, it costs around 41p to run an average 4kW gas fire for 1 hour.

If you ran this gas fire for one hour every day, your monthly costs will be £12.36.

I took a look at my gas fire and was slightly shocked to find that it consumes 6.9kW!

To run my gas fire it costs me 71p an hour. I imagine would very quickly mount up if I had it on for long stretches.

Do you want to know how we got to this number? Let me explain so you can easily calculate the costs of your gas fire too.

dog in front of gas fire
Murphy certainly enjoys the gas fire

3 factors affecting gas fire running costs

There are 3 primary factors that are involved in calculating your gas fire running costs:

  1. Heat input of the gas fire (the size)
  2. Price of gas – currently in the UK this is 10.3p per kWh
  3. How much you use it – generally calculated in hours

1. Heat input of a gas fire

The heat input is important when calculating costs as this is how much energy your gas fire requires to work over an hour.

The heat input is always calculated in kilowatt hours (kWh).

It’s important to note from a user point of view, that the heat input will be higher than the heat output into the room. This is where efficiency come into play. The most efficient your fire, the closer the output will be to the input.

There are many types of gas fireplaces you can buy today including:

  • Full depth
  • High efficiency
  • Wall mounted
  • Hole in the wall
  • Flueless
  • Freestanding
  • Slimline

With all the types, they can still be categorised as small, medium and large gas fires. The size refers back to the heat input/output – it’s this that you need to know.

Small gas fire

On average, a small gas fire has a heating input of 2-4kWh.

At this capacity, the hourly cost will range from 21p – 41p an hour.

Ran for an hour a day over the course of a week will cost you £1.44 – £2.87.

Medium gas fire

A standard or medium-sized gas fire will have a heating power of 4-6kWh.

The cost per hour to run a medium gas fire ranges from 41p – 62p.

Over a week if ran for an hour a day, you’ll pay £2.87 to £4.32.

Large gas fire

A gas fire is considered large if it has a heating power of anywhere from 6-12kWh. Some gas fires can even be higher than this.

The cost per hour to run a large gas fire will range from 62p – £1.24.

Using a large gas fire for an hour a day will cost you between £4.32 and £8.65 over a week.

2. Price of gas

The current price of natural gas used to run a gas fire is 10.3p per kWh.

However, there’s no guarantee that it’ll remain this way for the next few years.

Household natural gas prices have more than doubled since 1995 and are likely to increase in the near future with inflation, wars and other factors.

This being said, less natural gas is being used overall, with more appliances shifting across to electricity.

3. Frequency and duration of use

How often and how long you keep the gas fire running is the most obvious factor affecting the running cost of your fireplace.

Keep your gas fire on for longer and you’ll pay more.

gas fire close up
Gas fire and safety guard for the dogs and babies!

Calculation for gas fire running costs

So, how much does a gas fire cost to run?

If you’re looking to calculate the specific cost of your own gas fire and the above didn’t cover it, here’s the formula.

Heat Input (kWh) x Price of Gas x Duration of Use (hours) = Gas Fire Running Cost

To give you an example:

5kW x 10.3p x 2 hours = £1.03

It’s important to keep the units the same. So, if you’re putting the heat input in kWh as you should, calculate the duration in hours too.

If you only have the gas fire on for 30 minutes, you’d multiple by 0.5 (half of an hour). If you have the gas fire on for an hour and a quarter, this would be 1.25.

Accounting for gas fire efficiency

Sometimes it isn’t clear exactly what the heat input is.

However, the gas fire model should definitely state the heat output (that goes into the room) or the efficiency of the fire.

A gas fire is never 100% efficient.

In reality, a gas fire will only be somewhere between 60 to 90% efficient. This is how much of the energy input is converted to heat energy in the room.

So, if you have a gas fire with a heat input of 5kW that is 75% efficient, you’ll be getting 3.75kW of heat output into your room.

Let’s compare: Gas Fire vs Electric Fire

Ok, we’ve had a look at gas fire running prices, but how do they compare to the running costs of electric fires?

Another good option in the heating world are electric radiant heaters. The newer models are very slick looking and consumer similar amounts of power to electric fires. Let’s dive into the comparison.

electric fire in media wall
Electric fire in media wall

Heat output

Gas fireplace models can generate between 2kWh and 12kWh of heat energy.

Meanwhile, an electric fireplace is generally powered by just 0.7kWh to 2kWh of energy.


The kicker with electric fires, and electricity in general, is that it costs much more than gas per unit.

Currently, the price per kWh for gas is 10.3p.

The price per kWh for electricity is 34p.

Let’s run the calculations again.

Example for running a 5kW gas fire for 2 hours:

5kW x 10.3p x 2 hours = £1.03

Example of running a 1.5kW electric fire for 2 hours:

1.5kW x 34p x 2 hours = £1.02

On this basis, there is very little difference between the running costs of a gas vs electric fire.

Energy efficiency

Electric fires are low wattage appliances with very high energy efficiency conversion.

Because there’s no actually burning of a fuel – it’s just the heating of coils – there’s no need for a vent, unlike gas fires.

In other words, there’s zero, or at least a very small, amount of heat loss with an electric fireplace.

In fact, some electric fires are 100% efficient!


There’s a wide array of designs for both types of fireplaces to match the ambiance of your home. So, it all comes down to personal preferences.

However, you should consider that gas fires generate actual flames, which some may prefer over an electric fireplace’s artificial flames. Some electric models, though, may have crackling sounds to make them even more realistic.

Also, with electric fires you can turn on the artificial flames without the heater. This can either help to set the mood or psychologically trick you into being warmer!

Keeping the heat in your home

If you are going to put the gas fire on, central heating or wood burner, it’s important to keep as much heat inside your home as possible.

This is all to do with the efficiency of your heat source and your home’s insulation.

Blocking up the draughts and using thermal curtains really do help. Bigger projects might include installing eco insulation to your walls, flooring and roof.

The main point is to not let all that heat energy escape!

Before you go…

With the costs of everything going up, energy efficiency is a hot topic at the minute (pardon the pun).

Choosing a good energy efficient appliance can help to save you potentially £100s over the course of a year.

For example, you can run a new energy efficient fridge for around £40 a year. An old inefficient fridge freezer will cost 10 times this annually.

Same applies for eco kettles and electric ovens.

Of course, buying a new efficient model will come with an upfront cost so it all needs to be balanced out and considered carefully.

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Ben & Murphy Peaks Mam Tor

I’m the Creator and Editor of Tiny Eco Home Life. I write and publish information about living a more sustainable, environmentally friendly life. Away from the laptop, I love spending time in nature and with my young family (plus Murphy the dog!). I write and send out the Eco Life Newsletter.