What is it actually costing you to leave that on?

The questions people ask first

Your bill, in full

How UK electricity rates and the energy price cap work

In the UK, electricity prices are regulated by Ofgem through the Energy Price Cap, which sets the maximum amount suppliers can charge per unit of energy on default tariffs. The cap is reviewed and updated quarterly (January, April, July, and October). It does not cap your total bill; rather, it caps the unit rate (price per kWh) and the daily standing charge. Your actual bill depends on how much energy you use.

Under the Ofgem price cap for 1 October to 31 December 2026, electricity on a standard variable tariff paid by direct debit is 26.32p per kWh with a daily standing charge of 54.83p. Gas is 7.97p per kWh with a standing charge of 29.68p per day. The electricity figures carry no VAT, because VAT is removed from electricity bills from 1 October 2026 to 31 March 2027, and the gas figures include 5% VAT. The calculator above follows the period you are in. The cap is reset every three months based on wholesale energy costs, network charges, and policy costs, so check Ofgem's unit rate page for the figures in force now. You can often find cheaper rates by switching to a fixed-rate tariff when wholesale prices are falling, though fixed tariffs carry the risk of locking in a higher rate if prices subsequently drop.

Understanding kWh and how energy is billed

A kilowatt-hour (kWh) is the standard unit used to measure energy consumption in the UK. One kWh is the amount of energy used by a 1,000-watt appliance running for one hour. For example, a 2,000W electric heater running for 30 minutes uses 1 kWh, while a 100W light bulb running for 10 hours also uses 1 kWh.

Your energy bill is calculated by multiplying the number of kWh you have used by the unit rate, then adding the daily standing charge. So if you use 250 kWh of electricity in a month at 26.32p per kWh, the energy cost is £65.80, plus £16.45 for the standing charge (54.83p times 30 days), giving £82.25. Electricity carries no VAT in this period, so that is the bill rather than a figure to add VAT to.

To convert an appliance's wattage to kWh, divide the wattage by 1,000 and multiply by the number of hours it runs. The calculator above does this automatically for you and shows costs at daily, monthly, and annual levels.

How to read your energy meter

Knowing how to read your meter helps you track energy usage and check your bills are accurate. The UK has three main types of meter:

• Digital meters: Simply read the numbers from left to right, ignoring any numbers after a decimal point or in red.
• Dial meters: Read each dial from left to right. If the pointer is between two numbers, use the lower number. If it is between 9 and 0, use 9 and reduce the previous dial reading by one.
• Economy 7 meters: These have two rows of numbers showing day (normal) and night (low) rates. Read both rows separately.
• Smart meters: These send readings automatically to your supplier. You can view your usage on the in-home display (IHD) in real time, showing both kWh used and the cost in pounds.

To calculate your usage between readings, subtract the previous reading from the current one. The difference is the number of kWh you have used in that period.

The most expensive appliances to run in the UK

Some appliances consume far more energy than others. Understanding which items cost the most helps you target your energy-saving efforts effectively. Here are the biggest energy consumers in a typical UK household, based on average usage patterns and the price cap electricity rate of 26.32p per kWh for 1 October to 31 December 2026:

• Electric shower (8,500W): A 10-minute shower costs roughly 37p. Two showers per day for a family of four adds up to around £1,090 per year.
• Electric oven (2,000-2,500W): Using the oven for one hour costs about 53-66p. Used daily, that is approximately £190-£240 per year.
• Tumble dryer (2,500-4,000W): Each cycle costs around £1.11-£1.66. Running three cycles a week adds up to roughly £170-£255 per year.
• Electric hob (1,500-2,000W): Cooking for 30 minutes costs about 20-26p. Daily use totals approximately £72-£96 per year.
• Immersion heater (3,000W): Running for 2 hours per day costs about £1.58, or roughly £580 per year.
• Kettle (2,000-3,000W): Each boil costs about 3-6p, but boiling 5 times a day adds up to £60-£100 per year.
• Fridge-freezer (150-300W): It is plugged in 24/7, but the compressor cycles on and off rather than drawing its full wattage all day. A typical 150W model uses about 394 kWh a year, which is about £104 at 26.32p per kWh.
• Washing machine (500-2,000W): Each cycle costs about 27-54p. Five washes a week totals £71-£143 per year.

Energy saving tips by room

Kitchen

• Use a microwave or air fryer instead of the oven for smaller meals; they use up to 75% less energy.
• Only boil the amount of water you need in the kettle. Boiling a full kettle when you only need one cup wastes about 2p each time.
• Keep your fridge between 3-5 degrees Celsius and your freezer at minus 18. Every degree colder uses more energy.
• Let food cool before placing it in the fridge or freezer, as warm food forces the appliance to work harder.
• Run the dishwasher only when full, and use the eco setting which washes at a lower temperature.

Living Room

• Switch off the TV at the wall rather than leaving it on standby. A TV on standby can use 5-10W continuously.
• Replace halogen bulbs with LEDs. An LED bulb uses about 7W compared to 50W for a halogen, saving around £5.50 per bulb per year.
• Use a smart power strip to automatically cut power to devices in standby mode.

Bedroom and Bathroom

• Reduce shower time by one minute to save roughly £22 per person per year on an electric shower.
• Do not leave heated towel rails on 24/7; use a timer so they are only on when needed.
• Charge devices overnight and unplug chargers when not in use. Phone chargers draw a small amount of power even when nothing is connected.

Laundry

• Wash clothes at 30 degrees instead of 40. Modern detergents work just as well at lower temperatures and you save about 40% of the energy per cycle.
• Use a clothesline or drying rack instead of the tumble dryer when possible. A tumble dryer is one of the most expensive appliances to run.
• Clean the lint filter in your tumble dryer after every use to maintain efficiency.

Smart meters and time-of-use tariffs

Smart meters are the next generation of gas and electricity meters. They send automatic readings to your supplier, ending the need for estimated bills or manual readings. In the UK, the smart meter rollout is well underway, with the goal of offering one to every home. There is no charge for the meter itself, though the costs are built into energy bills for all customers.

One significant benefit of smart meters is that they enable time-of-use tariffs. These tariffs charge different rates depending on when you use energy. Off-peak hours (typically overnight and early afternoon) are cheaper, while peak hours (usually 4pm to 7pm) are more expensive. If you can shift energy-intensive activities like running the washing machine, dishwasher, or charging an electric vehicle to off-peak times, you could reduce your bills noticeably.

The in-home display (IHD) that comes with a smart meter shows your energy usage in real time, both in kWh and in pounds and pence. Many households find that simply being able to see what they are spending encourages them to reduce usage. Studies suggest smart meters with IHDs lead to average energy savings of 2-3%, and some households save considerably more by actively monitoring and changing their habits.

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