Estimate your next gas bill from your meter readings, unit rate, and standing charge. Gas meters measure in cubic metres (m³), and the calculator converts to kWh using Ofgem standard factors.
m³
m³
p
p
Days
Total cost (inc. VAT):
£0.00
- My meter shows cubic metres, why does the result show kWh?
- Gas meters measure the volume of gas you use in cubic metres (m³), but energy suppliers charge in kilowatt-hours (kWh). To convert m³ to kWh, the calculator applies the standard UK billing formula using a volume correction factor of 1.02264, a representative calorific value of 39.5 MJ/m³, and a final division by 3.6 to convert megajoules into kilowatt-hours. These factors adjust for the gas's energy content and for the difference between meter conditions and standard temperature and pressure. If your supplier's figure still doesn't match, see why your result may differ from your actual bill.
- Where do I find my unit rate and standing charge?
- Both figures appear on your gas bill or your energy supplier's website. Your unit rate is the price per kWh of gas you consume. The standing charge is the daily fixed fee shown separately on your bill, usually listed in pence per day.
- Does the estimate include VAT?
- The total shown includes VAT at 5%, which is the reduced rate applied to domestic gas in the UK. VAT is calculated on the combined usage cost and standing charge before being added to give the final total.
- What counts as a typical gas unit rate in the UK?
- As of early 2026, the Ofgem price cap sets gas unit rates at around 6–7p/kWh for most households on default tariffs. Rates vary by region and whether you're on a fixed or variable tariff, so check your bill or supplier account for the exact figure that applies to you.
- Why is my result different from my actual bill?
- This calculator estimates your bill from the inputs you provide. Your actual bill may differ for several reasons:
- Your supplier may apply additional network charges or levies not covered here.
- Estimated meter readings from your supplier can differ from actual readings.
- Some suppliers apply VAT differently or include other adjustments.
- What is a standing charge?
- The standing charge is a daily fixed fee that covers the cost of maintaining and operating the gas network connection to your home. It applies regardless of how much gas you use, even on days when you use none at all. The amount is set by your supplier and shown in pence per day on your bill.
- Can I use this for a smart meter?
- Smart meters still record gas consumption in cubic metres (m³) at the meter itself, so you can read the m³ figures and enter them as your previous and current readings as normal. Some in-home displays show usage in kWh. If that's the case, the conversion has already been done and you should use those kWh figures directly with a kWh-based calculator instead.
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