Gas Heating Running Cost Calculator

Estimate gas heating costs from measured gas kWh or the useful heat your home needs. Add heating days, your gas tariff and the standing charge to see the annual cost and monthly average.

How to use Gas Heating Running Cost Calculator

1. Choose the currency used for results. 2. Choose consumed gas when your energy figure is already in billed kWh. Choose useful heat only when you need boiler efficiency to convert heat output to purchased gas. 3. Change a value to update the results, or select Calculate. Review the chart and notes with the total. 4. Use Copy results, Share results or Download result graphic to keep the answer. Shared links include your figures. 5. Reset restores the editable example inputs.

Why use this tool?

A boiler’s maximum power does not tell you how much gas it burns across a heating day. A measured kWh figure gives a clearer starting point. When the information instead describes useful heat delivered to the home, the efficiency assumption accounts for the additional gas required. The calculator separates the heating usage cost from the fixed standing charge. That helps you see what reducing heating use could change and what is paid even on a day without heating. Include cooking and hot water only if you intentionally want them in the energy input.

How the calculation works

Consumed-gas mode: annual heating kWh = daily gas kWh × heating days. Useful-heat mode: annual gas kWh = daily useful heat ÷ (efficiency ÷ 100) × heating days. Usage cost is annual gas kWh × gas unit rate. Standing cost is the daily standing charge × the days it is paid. The annual estimate adds both costs. Monthly and daily outputs are budgeting averages over twelve months and 365 days. Gas already measured in kWh must not be divided by efficiency again, because its boiler losses are already part of the consumed energy.

Example

At an illustrative £0.07/kWh, 40 kWh of consumed gas on each of 180 heating days costs £504. Add 365 daily standing charges of £0.30 for a total of £613.50, or £51.13 per average month. The standing charge remains even when the heating usage falls.

Practical tip

Use gas kWh from a bill or an appropriately converted meter reading. A reading in cubic metres or cubic feet is a volume and cannot be entered directly as kWh.