Gas & electricity meter reading calculator

Enter two readings to see how much energy you used and what it cost. This is handy for checking a bill or your direct debit.

Days between readings

Electricity

First reading (kWh)

Second reading (kWh)

Unit rate (p/kWh)

Standing charge (p/day)

Gas

First reading

Second reading

Meter type

Calorific value (MJ/m³, on your bill)

Unit rate (p/kWh)

Standing charge (p/day)

Pre-filled rates are the Ofgem price cap GB averages for Direct Debit, 1 October to 31 December 2026 (source). Your own tariff and region may differ, so use the rates on your bill.

How gas units become kWh

kWh = cubic metres used × 1.02264 (volume correction) × calorific value ÷ 3.6. Imperial meters measure hundreds of cubic feet, so multiply the units by 2.83 first to get m³.

UK Bills & Budget Planner: £7
A Google Sheets and Excel planner that turns every bill into a monthly cost, and covers council tax, energy readings, a monthly budget and a savings goal.
See the template →

We make and sell this template (Tidy Life Templates).

FAQs

Why is my gas bill in kWh when my meter shows m³?

Suppliers convert the volume of gas into energy using the calorific value. The calorific value changes slightly over time and is printed on your bill.

How do I know if my meter is metric or imperial?

Metric meters show 'm³' and usually have 5 digits before the decimal point. Imperial meters show 'ft³' and usually have 4 digits.