If you want to compare energy tariffs properly, one of the most useful pieces of information is how much energy your household actually uses.

Not how much you pay by Direct Debit.

Not the balance on your energy account.

And not the amount an average household uses.

We're looking for your energy consumption, normally shown in:

kilowatt hours (kWh).

For a dual-fuel household, that means finding two numbers:

Annual electricity usage: ___ kWh

Annual gas usage: ___ kWh

Those figures give you a much better starting point for comparing what different tariffs could cost.

Where should you look on your energy bill?

There isn't one identical bill layout used by every UK energy supplier.

So don't worry if your bill doesn't look exactly like an example you've seen online.

Look instead for wording referring to your annual consumption, annual usage, estimated annual usage, energy usage or consumption over the last 12 months.

Ofgem defines an Annual Statement as containing key tariff information including consumption over the previous 12 months and an estimate of annual cost for the following 12 months.

The important things to identify are:

the fuel — electricity or gas

the consumption figure

and

the unit — kWh

For example:

Electricity
Estimated annual usage
2,399 kWh

and:

Gas
Estimated annual usage
7,914 kWh

Those are the kinds of figures we're looking for.

Don't mistake £ for kWh

This is probably the most important distinction.

Your bill contains several numbers expressed in pounds.

For example:

Direct Debit: £140/month

Account balance: £86 credit

Estimated annual cost: £1,620

None of those is your annual energy consumption.

We're looking for a number followed by:

kWh

Ofgem explains that the unit price for electricity and gas is charged against energy measured in kilowatt hours.

So:

£1,620

is money.

While:

9,000 kWh

is energy consumption.

You need to keep the two separate.

Electricity and gas have separate usage figures

If your home uses both mains gas and electricity, don't look for one combined annual kWh number.

You normally need:

electricity consumption in kWh

and:

gas consumption in kWh

separately.

That's because electricity and gas have different unit rates.

For example, imagine your bill shows:

Electricity annual usage: 2,500 kWh

Gas annual usage: 9,000 kWh

A tariff might charge:

Electricity: 25p/kWh

Gas: 6.5p/kWh

The two consumption figures therefore have to be calculated separately before the costs are combined.

Don't confuse annual usage with usage for this bill

Your bill may contain several different kWh figures.

Suppose you receive a bill covering three months.

It might say:

Electricity used this period: 620 kWh

That tells you how much electricity was used during that billing period.

It does not necessarily mean your annual electricity usage is 620 kWh.

Elsewhere on the bill you might find:

Estimated annual usage: 2,500 kWh

For tariff comparison, it's generally the annual figure we're interested in.

What if your bill doesn't show an obvious annual figure?

First check other sections of the bill.

Depending on the supplier, annual consumption information may appear near:

• tariff information

• energy usage

• your usage

• personal projection or estimated annual cost

• tariff comparison information

• electricity or gas details

• an annual summary

If you use an online account or supplier app, you may also be able to view your consumption history there.

Ofgem says that when switching supplier, information needed includes the amount paid per unit and the amount of energy you use each year, information available from your energy bill.

What if you've been with the supplier for less than a year?

This is where the word estimated becomes important.

If there isn't a complete 12 months of consumption history, the supplier may need to estimate annual usage using the information available.

That doesn't make the number useless.

But it means you should understand that it isn't necessarily twelve months of directly observed consumption.

Ofgem's Estimated Annual Cost methodology uses actual historic consumption where available and a best estimate where it isn't.

For comparison purposes, the question is:

Is this the best reasonable estimate of what my household is likely to use?

Check whether your meter readings are actual or estimated

There is another distinction worth making.

A bill can contain an annual consumption estimate that has itself been influenced by estimated meter readings.

If your supplier doesn't have an actual meter reading for part of the billing period, it may estimate how much energy you've used.

That can make the underlying consumption less reliable.

If you have a functioning smart meter sending readings automatically, the supplier may already have regular actual readings.

If not, providing meter readings can improve the information used to calculate your bills.

Don't use the meter reading itself as your annual usage

This is an easy mistake to make.

A meter might display something such as:

Electricity meter reading: 18,462

That doesn't mean you used 18,462 kWh during the last year.

A meter reading is a cumulative reading.

Consumption is calculated from the difference between readings over time.

For example:

Earlier reading: 15,962

Later reading: 18,462

Difference:

18,462 − 15,962 = 2,500

So consumption over that period was:

2,500 kWh

The reading itself and the amount consumed are different things.

Gas bills can look more complicated

Gas can be particularly confusing because a gas meter doesn't necessarily display energy directly in kWh.

The meter measures a volume of gas.

Your supplier converts that volume into kWh for billing purposes.

So for tariff comparison, don't simply take the number displayed on the gas meter and treat it as annual gas kWh.

Look for the kWh consumption figure on the bill.

That's the figure to which the gas unit rate is applied.

What about the “typical household” figures?

If you don't know your own consumption, you may encounter standard figures representing a typical household.

These are called Typical Domestic Consumption Values, or TDCVs.

Ofgem uses them to help illustrate what low, medium and high energy consumption can look like and as part of price-cap calculations.

From 1 July 2026, the medium values are:

Electricity: 2,500 kWh per year

Gas: 9,500 kWh per year

These figures can be useful when personal consumption information isn't available.

But they don't mean your household uses those amounts.

Energy UK specifically recommends using your own annual consumption figures where possible when comparing tariffs or estimating bills.

Why your own annual usage matters

Imagine Household A uses:

1,500 kWh electricity

while Household B uses:

5,000 kWh electricity

A tariff with a low standing charge but higher unit rate might work well for Household A.

A tariff with a higher standing charge but lower unit rate might work better for Household B.

We demonstrated exactly this in our guide to energy unit rates vs standing charges.

That's why knowing your own consumption is so useful.

It allows different tariffs to be tested against the same household rather than against a generic national average.

What information should you take from your bill?

For a straightforward tariff comparison, I'd start by recording:

Electricity

• annual usage in kWh

• unit rate

• standing charge

Gas

• annual usage in kWh

• unit rate

• standing charge

Then also note:

• tariff name

• tariff end date, if applicable

• exit fees, if applicable

• payment method

That gives you much more useful information than simply recording:

“I pay £140 a month.”

As we explained in Should you compare energy tariffs using your Direct Debit or your actual kWh usage?, a monthly Direct Debit is a payment arrangement and shouldn't automatically be treated as the cost of your consumption.

What if your usage is going to change?

Your historic annual consumption is a starting point, not a prediction guaranteed to come true.

Your future consumption could change if, for example, you:

• buy an electric vehicle

• install a heat pump

• install solar panels or a battery

• start working from home

• change the number of people living in the property

• substantially change how you heat your home

In that situation, last year's kWh may need adjusting when estimating future tariff costs.

The aim isn't to pretend we know exactly how much energy you'll use next year.

It's to use the best reasonable consumption estimate available and apply it consistently to the tariffs being compared.

The four numbers worth finding first

If you have a dual-fuel bill in front of you, start with these:

1. Annual electricity usage — kWh

2. Electricity unit rate — p/kWh

3. Annual gas usage — kWh

4. Gas unit rate — p/kWh

Then find the electricity and gas standing charges.

With those figures, you already have much of the information needed to make a meaningful tariff comparison.

Eventually, you shouldn't have to hunt for these numbers

This is one of the problems Likewise Compare is being built to solve.

Energy bills can contain a lot of information, and different suppliers don't necessarily present it in exactly the same way.

Rather than asking you to understand every section of an energy bill, the aim is for Likewise Compare to let you provide your bill or renewal information and identify the relevant tariff and consumption data needed for comparison.

You should still be able to see and check the information being used.

Because whether the figure appears on page one or page four isn't really what matters.

What matters is finding the right figure and comparing tariffs on the same basis.

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