How much does it cost to boil a kettle? Plus, the cheapest ways to boil water

As energy prices are set to go up, here's how much it costs to boil your kettle

A chrome kettle poring water into a black mug
(Image credit: Getty Images)

Boris Johnson has sparked outrage after suggesting Britons buy a new kettle to save money on their energy bills, and his comment has left many asking how much does it cost to boil a kettle?

With the energy price cap (opens in new tab) set to be replaced by the newly announced Energy Price Guarantee in October, (which means average energy prices won’t rise by the 80% previously reported, but instead will be frozen at £2,500 based on typical use for the next two years), many people are still searching for ways to save energy at home in the fight against the rising cost of living.’s Money Editor, Sarah Handley (opens in new tab) says: “Liz Truss’ announcement of the Energy Price Guarantee (opens in new tab) will have been good news to households across England Scotland and Wales, who were braced for energy prices to skyrocket by a whopping 80% in October (and probably rise again in 2023). But, while average bills for typical use will be frozen at the £2,500 mark, that’s still more expensive than what we were paying at the end of 2021.

“Many families will still struggle to afford their energy bills. And while it’s not a fix all solution, knowing how much your most often used appliances cost to run can only help highlight where you might be using more energy than you need to ”

As the weather gets colder, our energy use is only going to increase and something as simple as making a cup of tea could be wasting precious pennies. To make sure you're saving everything you can, we've looked at how much it costs to boil a kettle and the cheapest ways to boil water.

How much does it cost to boil a kettle?

To boil a cup of water in a kettle, it will currently cost you about 1.05p, based on an average 3kW kettle taking around 45 seconds to boil. That is based on the current price for a unit of electricity being 28p per kWh. But from 1 October, this will rise to 34p per kWh. This means the cost of boiling a cup of water in the same kettle will rise to 1.28p. 

When it comes to boiling a full kettle, it’s understandably more expensive. Most kettles can boil around 1.7 litres of water at a time in about four minutes. Until 30 September, you can expect to pay 5.6p each time you boil a full kettle. From 1 October, when the Energy Price Guarantee unit rates come into force, you can expect to pay 6.8p to boil a full kettle. 

If you had two cups of tea every day for a year, and only boiled the water you needed, based on the costs from 1 October onwards, it would cost you £9.34. But if you boiled a full kettle each time, it would cost you £49.64. So it’s definitely more cost effective to only boil the amount of water you need, rather than a full kettle. 

Cost per cup (from 1 October)Cost per full kettle (from 1 October)
3kW kettle1.28p6.8p
Annual cost if you had two hot drinks a day£9.34£49.64

Are some kettles cheaper to boil than others?

Some kettles will be more energy efficient than others, which means they are cheaper to boil.

For example, kettles with poor insulation will be losing heat as they boil and therefore take longer to reach boiling point. Additionally, limescale reduces the efficiency of kettles and can mean it will take longer to boil.

Energy saving features to look out for when buying a kettle

  • Variable temperatures - Some kettles will allow you to heat water to temperatures lower than boiling, which uses less energy. It's not always necessary for the water to be at 100 degrees, so consider a kettle that can heat water to lower temperatures too.
  • Low minimum fill - It's always cheaper to boil less water, so kettles with a lower minimum marker will save you money if you're heating water for just one cuppa.
  • Water level gauge - A kettle with a transparent window that clearly marks how much water you're boiling will help you avoid wasting energy by boiling more than you need.
  • Removable filter - Because limescale reduces the efficiency of kettles, choosing one with a removable filter will make it easier to descale and help save energy.

An open kettle with limescale in the bottom

(Image credit: Getty Images)

Cira Jones (opens in new tab), Assistant Brand Manager at Russell Hobbs, says: "A clear window with cup markings allows you to see how much water is in the kettle so you don’t boil more water than you may need. This is one of the best ways to save energy when it comes to your kettle. 

"A variable temperature kettle is also a good way to only use the amount of energy you need. Being able to set your kettle to heat water at any temperature from 40°C up to 100°C to means you can make a speciality tea without spoiling its delicate flavours, gently heat a baby’s bottle - or go ‘red hot’ to make a strong tea or coffee." 

Is it cheaper to boil water in a kettle or on the hob?

Whether it is cheaper to boil water in a kettle or on the hob will depend on what kind of hob you have. If you have an electric hob, it will cost about the same amount as an electric kettle. However, if you have a gas hob, it is cheaper to boil water on the hob than in a kettle, because gas is cheaper per kWh than electricity.

Make sure you're using a high heat and putting a lid on the pan of water for the most efficient way to boil it, and measure out the water first so you're not boiling more than you need.

Additionally, according to recent research (opens in new tab) by energy supplier Utilita (opens in new tab) and supermarket chain Iceland (opens in new tab), letting water simmer rather than leaving it boiling can save £68 annually. 

How to save energy when boiling a kettle

  • Don't overfill the kettle - The more water you boil, the more energy you use, so make sure you're only filling the kettle with the water you need.
  • Descale regularly - Getting rid of limescale will improve the efficiency of your kettle. You can buy limescale remover from the supermarket, but you can also fill your kettle half with water and half with white vinegar and leave it to soak.
  • Unplugging the kettle when it's not in use - Leaving devices plugged in at the socket can mean they are still using a small amount of power, so unplugging your kettle from the wall when you're not using it can save some energy. 

You might also be interested in our other appliance running cost articles including:

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