There are many ways to calculate your gas and electricity bill. Our useful information guide will help you understand how to calculate how much your energy bill is going to cost you.

Your bill will vary based on many factors including:

  • Your energy consumption levels
  • Payment method (Direct Debit or cash/cheque)
  • The tariff you're on
  • The supplier you're with
  • Your unit rates (which vary based on region)
  • Discounts that may/may not be applied


Some customers find it difficult to determine exactly how much their bills will cost when they use online comparison tools. These tools are always dependent on the information that you put into them, which means it can result in customers being given incorrect information or even inaccurate quotes if you enter the wrong information. Take your time to fill in our energy price calculator with your accurate consumption, tariff and meter information to get an accurate price from British Gas today.

At British Gas we aim to be open about our energy prices. By viewing our tariff range you can find out all of the average prices across all regions for each of our tariffs. This will help give you an idea of how much you’ll be paying if you were to consume the average amount for an energy user in the UK.

Understand your unit rates

Your unit rates are an important part of how your bill is calculated. We have recently changed our pricing structure to include a standing charge and a single unit rate to make it easier to understand how much you’re paying. A standing charge is a fixed amount that is applied to your gas and electricity bill daily. For any tariff with a standing charge you will pay a daily charge and a single unit rate making it easier to understand how much you’re paying.

Check our tariff rates page for more information about our gas and electricity tariffs.


One of the benefits of signing up both your gas and electricity with British Gas is that you receive £15 discount a year off your energy bill[1]. Our latest gas and electricity tariffs have a Direct Debit discount built into the unit rates so if you choose to pay this way your prices will be cheaper bringing the cost of your energy down.

The £15 Dual Fuel discount will be taken off your bill each year and the direct debit discount is built into your unit rates. These two factors also impact exactly how much your final bill will be.

[1] Where we supply gas and electricity to the same customer at the same property you’ll receive one Dual Fuel discount. Where electricity is supplied through a credit meter, you’ll receive a discount of £15 per year applied to your bill, pro-rated across your billing period.