How much electricity does a kettle use? The cost of making a cup of tea

As the cost of living crisis hits hard, many are wondering 'how much electricity does a kettle use?' as even the price of boiling a kettle can start to seem like an extravagance.

As temperatures drop and energy prices rise, many Brits will be relying on a steady flow of hot drinks to keep the chill at bay. And let’s not forget the cosiness of a warm hot water bottle on a cold winter night. 

However, in these price-crunching times, many people are looking to save pennies wherever possible. So how much electricity does a kettle use? And is an electric kettle the most cost-effective way to fix yourself a brew? 

We break down the running costs of your tea or coffee break, and offer some energy saving tips from the experts.

How much electricity does a kettle use?

Not all kettles are created equal, and the amount of electricity your kettle uses will depend on factors such as the energy efficiency rating of the model, and how many litres of water it holds. But as a general guide a kettle usually has a maximum power output of 3000 Watts. In fact when we did a bit of digging on John Lewis we found most kettles have a maximum power output of 3000W.

You can also get kettles that offer superfast boiling like this Smeg kettle on John Lewis with a water capacity of 1.7 litres as well as more affordably priced models like this hive kettle by Morphy Richards, both of which have a 3000W power output.

As of early October, UK energy price rises soared to an average of 34p per kWh, up from 28p per kWh previously. And with many people still working from home post-pandemic, the cost of those hot drinks can stack up.

Find out how you can save on your energy bill with the energy grants available. 

Is it expensive to boil a kettle? 

We calculated that it costs 7p to boil a full kettle (1.7 litres), which is enough for a good six mugs of tea. That cost reduces if you put less water in the kettle as the cost is very much related to how long the kettle takes to boil.

To calculate how much your kettle costs to boil, you need to follow the following steps:

• Look at how many watts or kilowatts your kettle uses
• Convert watts into kilowatts by dividing by 1,000
• Time how long it takes your kettle to boil in seconds
• Divide the kWh figure by 3600 to get the energy usage per second rate
• Multiply by the time in seconds to calculate energy usage
• Multiply this figure by your electricity cost in £s

If we apply this calculation to a 3000W Russell Hobbs kettle (I tested out my own) that took 3 minutes 49 seconds – 229 seconds in total – to boil 1.7 litres of water, it comes out with a cost of 7p. To break that down:

1. The power of the kettle is 3000W/1000 = 3kW
2. The energy consumption is (3kWh/3600) x 229 seconds = 0.19kWh
3. The cost of boiling the kettle is 0.19kWh x £0.34 = £0.065 or 7p rounded up

Therefore, how much your kettle costs to boil is linked to a number of factors that affect the price of boiling your kettle: 1) The type of kettle you use and its energy efficiency, 2) How many litres it hold, 3) Your energy provider and their charges, and 4) How full the kettle is each time you boil it.

If you're curious about how to save money on other appliances, take a look at our guide to the cost of running a tumble dryer. 

Why does a kettle use so much electricity?

Although the kettle ranks among the biggest energy guzzlers in British households, much of this is energy use is down to consumers routinely overfilling their kettles. 

Boiling a full kettle for one cup of tea is far from a cost-effective habit, but kettles themselves are not the biggest culprits in the kitchen - in fact, the Energy Saving Trust actually recommends using a kettle to boil water for cooking, rather than heating it on the hob. 

The energy experts at Russell Hobbs explain: “The majority of models only draw power whilst actually heating water, contrary to the popular belief that they are ‘vampire’ appliances that use energy whilst on standby. The main reason behind the high electricity consumption of kettles is simply that they are often boiled with more water than is needed.”

Find out what uses the most electricity in the home with our guide to different appliances. 

How can I save money when boiling hot water?

There are several simple steps you can take to keep your kettle costs down — that don't mean you have to kerb your hot drink habit to ease the squeeze. 

Don’t overfill your kettle. Uswitch.com energy expert Sarah Broomfield, says: “When making hot drinks, it is important to only fill your kettle with as much water as you need. The more water in the kettle, the longer it will take to boil and the more energy it will use. It’s important to get into good energy habits ahead of winter as small changes will help households take back some control over their energy spending.” 

Consider switching to an energy efficient model. If you’re using an older kettle, the chances are that it’s costing you time and energy. According to Which.co.uk, “If a kettle is able to reach boiling point in around three minutes, it will use far less
energy than one that takes four or five minutes to boil the same amount.”

Descale - and check the lid. According to Russell Hobbs’ kettle expert Cira Jones, descaling can cut costs. She says: “The build-up of limescale is a culprit when it comes to the energy efficiency of your kettle. Resulting from the natural build-up of minerals such as calcium carbonate, magnesium, and iron, limescale deposits act as an insulator. In turn, this forces the kettle to work a lot harder to heat itself. Homes that receive hard water are most at risk of limescale.”