How does the energy bill estimate work?

1. Start with what you know

Describe your home in a sentence and the AI interpretation service returns suggested annual electricity and gas kWh, reasons, assumptions and tips. If that service is unavailable, we say so and direct you to the manual home form; we never pass off a fallback as AI.

Prefer known annual kWh? Enter the readings from your supplier app or latest bill. A monthly Direct Debit entered alone can produce a very rough two-fuel illustration, assuming a medium-use electricity-to-gas split and no account credit or debt. A payment does not reveal actual consumption.

2. Calculate the annual cost

For each fuel, annual cost = (annual kWh × unit price in pence + 365 × standing charge in pence) ÷ 100. The tool adds electricity and gas for a combined annual total, then divides by 12 for an illustrative monthly average.

For home-based estimates, low and high scenarios move estimated usage by around 15%; current benchmark rates are managed separately from usage assumptions. Explicitly supplied annual kWh do not receive an artificial uncertainty band. The accessible fallback starts at 1,800/2,700/4,100 electricity kWh and 7,500/11,500/17,000 gas kWh, then adjusts for the home and selected behaviours.

3. Compare, then check the details

If you enter your own tariff's electricity and gas unit and standing rates, we calculate a separate annual comparison. A fixed deal below the cap may be worth checking, but consider its end date and exit fees.

Regional rates vary by a few percent. Actual use, meter type, payment method, tariff, and weather affect your bill. Oil and LPG fuel costs are outside this tool. We do not provide supplier offers or collect account details.

Sources and scope

The estimator uses a GB benchmark rate reference; period and current assumptions are available on the energy price cap page. For current regulation and consumer guidance, consult Ofgem and Citizens Advice directly. This personal tool is independent and is not a supplier, broker or comparison site.

Good to know

Does AI choose the energy prices?

No. Benchmark rates are managed separately from the AI, which only interprets likely annual usage and explains assumptions. See the current rates and period on the energy price cap page.

What happens when AI is unavailable?

You see an explicit message and can use the accessible home-details form or enter known annual kWh instead.

Why is there a low-to-high range?

Estimated home usage is uncertain, so the tool shows scenarios around 15% either side. Known annual kWh are not varied.

Is this a supplier quote?

No. It is an indicative calculation using GB average capped rates; your actual tariff and usage determine your bill.

Sources

• See the current energy price cap rates