Page last updated on 17th August 2026
Our FAQs: How to calculate your energy bill
Understanding your energy bill can feel complicated, especially as energy prices change. But learning how your bill is worked out can help you manage household spending, spot possible billing errors and keep track of your energy use.
This guide explains what appears on an energy bill, how tariffs affect what you pay, and answers common questions such as how much your bill might be and how the charges are worked out.
What is an energy bill and what is the average energy bill in Great Britain?
An energy bill is a document showing how much you owe for the gas and electricity used during a billing period. For many households, understanding your energy bill is an important step towards managing costs and avoiding unexpected charges.
According to Ofgem, from 1 July to 30 September 2026 the typical annual bill for a dual-fuel household in Great Britain paying by Direct Debit is £1,862 under the energy price cap. Ofgem reviews the cap every three months.
Last reviewed: June 2026
Key information about energy bills in Great Britain:
You receive these bills regularly, mostly monthly, but this can depend on your energy provider and the tariff you’re on.
They can be sent via post or electronically if you go paper-free.
If you need help translating your bills, you can use the Priority Services Register – or continue reading for more information about your energy bill.
Knowing how your energy bill is calculated can make it easier to track changes in your household energy spending over time. If you have ever wondered how your energy bill is calculated, the answer usually comes down to your usage, unit rates and standing charges.
What are the key sections of your energy bill?
Your bill layout may vary depending on your supplier, but it will usually include several key sections:
Basic information such as your name and address, the name of your energy supplier and a unique identifier or account number.
Tariff information and details including the tariff you are on for your gas and electricity supply. This can help you see whether you are on a fixed, variable or time-of-use tariff.
Usage breakdown including a record of your gas and electricity meter readings and your energy usage over a specific period. These usage figures will either be estimations, if no meter readings have been submitted, or based on how much has actually been used, if you have a smart meter installed or if a manual meter reading has been submitted for the billing period. If your supplier has used estimated readings, you may receive an estimated energy bill rather than a bill based on actual usage.
A breakdown of charges such as how much you owe your energy supplier, standing charges (a fixed cost to cover the cost of supplying your property with energy), unit rates set by your energy supplier (how much energy costs per unit) and sometimes how much you’ve previously paid. Understanding this energy bill breakdown can help you identify why costs may have increased compared to previous months.
Serial numbers for your gas and electricity meters.
What are the different types of energy tariff?
Want to know about the different types of energy tariffs and how to read your energy bill? Here are the most common ones:
Fixed-rate tariff
A fixed-rate tariff has a ‘fixed’ price that you pay for each unit of energy over a specified period. Fixed tariffs can help with budgeting as you’ll know exactly how much you are paying each month. But if the price of energy drops, you could end up paying more than necessary.
Standard variable rate tariff
A standard variable rate tariff is when the unit price of energy changes according to market conditions, typically every three months. Standard variable tariffs are much more flexible than fixed tariffs, but they require you to adapt to changes in the price of gas and electricity, which makes planning ahead more challenging. Your rates could go up or down. If you are on a standard variable tariff, your energy supplier should contact you if your rate changes.
Time-of-use tariff
Time-of-use tariffs offer fluctuating electricity rates depending on the time of day when you consume energy. During off-peak periods, such as late at night or in the morning, electricity can be cheaper. By adapting your energy usage habits, you can benefit from these tariffs and save on your energy bills. To be eligible for new time-of-use tariffs, you’ll need to get a smart meter to provide your energy supplier with accurate, regular meter readings.
What does an energy bill look like?
Learn more about your energy bill with the visual below. For a full description of the image text you can click on 'continue reading'.
What does the energy price cap mean for your energy bill?
What does the energy price cap mean?
The energy price cap is set by Ofgem, Great Britain’s independent energy regulator. It limits how much suppliers can charge for each unit of gas and electricity, and for the daily standing charge, on default tariffs.
What does the energy price cap mean for bills?
The price cap does not limit your total bill. It limits the unit rate and standing charge suppliers can charge, but what you pay overall still depends on how much energy you use.
What is the maximum energy bill cap?
No. There is no fixed maximum bill because the total you pay depends on how much energy your household uses.
That is why bills can vary so much from one home to another, even when households are on similar tariffs.
For more information about the current price cap, visit our price cap page or Ofgem’s website. As a reminder, Ofgem reviews the cap every three months.
How do I calculate my energy bill?
Your energy bill is usually based on your gas and electricity meter readings. If readings are not submitted, your supplier may generate an estimated energy bill using previous usage patterns.
How do I work out my energy bill step by step?
Step 1: Find your energy usage
Check your bill for the number of kWh units used during the billing period.
Step 2: Find your unit rate
Locate the price per kWh shown on your tariff information.
Step 3: Multiply usage by the unit rate
Energy units used (kWh) × your agreed unit rate = energy cost
This is the basic way to work out the energy cost shown on your bill. If you want to calculate energy bill costs yourself, this is the simplest place to start.
Example: calculate electricity bill from meter reading
If your electricity usage is 225 kWh and your electricity rate is 24.86p per kWh: 225 \times 0.2486 = 55.94
Using this formula can help you check the electricity charges shown on your statement.
Example: calculate gas bill from meter reading
If your gas usage is 958 kWh and your gas rate is 6.34p per kWh: 958 \times 0.0634 = 60.76
You can use the same method to check the gas charges shown on your bill.
Standing charges
Remember to include standing charges when working out total costs. Standing charges are fixed daily fees covering the cost of supplying your home with energy.
What is included in your final energy bill?
Your supplier will usually combine the following to work out your bill:
Your energy usage in kWh
Your agreed unit rate
Daily standing charges
Any previous balances or payments
This combined total forms your final bill.
If you are interested in working out the running costs of individual appliances, check out our guide on appliance running costs or use our energy cost calculator.
Your supplier may also include additional fees, such as standing charges or other services, to your total energy bill.
If you are interested in working out the running costs of individual appliances, check out our guide on appliance running costs or use our energy cost calculator.
What should I do if there are discrepancies on my energy bill?
If your energy bill is not in line with what you were expecting, it’s a good idea to double-check it to understand the charges and how much you have to pay. If you’re wondering how to read your energy bill to make sure it is accurate, follow these steps:
Check that the right home address has been listed and no mistakes have been made.
Check if the usage data is estimated – an estimated energy bill may be less accurate than a bill based on actual readings.
Check the tariffs and rates listed on your energy bill.
Compare your energy bill with a previous bill, to see if this is in line with what you would normally spend at this time of year.
If everything else is as expected, and you still think your bill does not look right, check that the meter serial numbers on your energy bill match the serial numbers on your actual gas and electricity meters.
Get a smart meter. They send meter readings directly to your energy supplier, eliminating the need for estimated bills and providing peace of mind that your bills are accurate. Additionally, its in-home display allows you to monitor your energy usage in near real-time, offering greater accuracy and control over your energy use.
If something doesn’t look right, don’t hesitate to reach out to your energy supplier and they can explain or rectify the issue. To escalate issues, please refer to our guide on how to make a complaint.
Learning how to read your energy bill may take a bit of getting used to, but it can help you take control of your energy bills and could support you in making savings. With our nation’s goal of achieving net zero by 2050, understanding your energy usage could also help you find ways to reduce your carbon footprint and save money.
FAQs
How much will my energy bill be?
The answer to how much will my energy bill be depends on your energy usage, tariff type, standing charges and current unit rates.
Can I calculate electricity bill from meter reading data myself?
Yes. You can calculate electricity bill from meter reading figures by multiplying your electricity usage in kWh by your unit rate.
How do I calculate gas bill from meter reading information?
To calculate gas bill from meter reading data, multiply your gas usage in kWh by the gas unit rate shown on your bill.
What is an estimated energy bill?
An estimated energy bill is created when your supplier does not have an actual meter reading and estimates your energy usage instead.
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