Free UK gas unit calculators for households, landlords & engineers. No signup. No ads. Just accurate results.
Enter your meter readings for an instant result. Full version with calorific value table →
14 free tools covering every gas unit conversion you'll ever need
Convert cubic metres to kilowatt hours using the official Ofgem formula. Enter meter readings for instant results.
Use Calculator →Reverse conversion — convert kWh back to cubic metres. Perfect for energy auditing and bill verification.
Use Calculator →Convert gas units to kWh for both imperial (cubic feet) and metric (cubic metres) UK gas meters.
Use Calculator →Complete guide and calculator for M3 to kWh conversion of natural gas with a 25-row reference table.
Read Guide →Estimate your UK gas bill from meter readings. Calculates energy cost, standing charge and 5% VAT.
Use Calculator →Calculate daily, weekly, monthly and annual gas consumption. Compare your usage against UK averages.
Use Calculator →Convert therms to kilowatt hours. 1 therm = 29.3001 kWh. Includes full reference table.
Use Calculator →Convert kilowatt hours back to therms. For UK/US gas billing format comparisons.
Use Calculator →Convert million BTU to cubic metres. Used in commercial gas trading and industrial LNG pricing.
Use Calculator →Convert British Thermal Units to cubic metres. 1 m³ ≈ 35,900 BTU. Bidirectional converter included.
Use Calculator →Imperial gas meter converter. Convert ft³ to kWh for older UK properties with imperial meters.
Use Calculator →Gas flow rate calculator for engineers and installers. Convert kilowatts to cubic metres per hour.
Use Calculator →Calculate your gas cost per cubic metre. Understand Ofgem price cap and current UK unit rates 2025.
Use Calculator →Complete step-by-step guide to converting gas units to kWh. Explains the official Ofgem formula simply.
Read Guide →Every calculator uses the same formula mandated by Ofgem for UK energy billing
Read your gas meter display and enter your current and previous readings. Works with digital, dial, and smart meters — both metric (m³) and imperial (ft³).
Our calculator applies the exact Ofgem formula: m³ × CV × 1.02264 ÷ 3.6. The calorific value defaults to 39.5 — check your gas bill for the precise figure.
Your energy usage in kWh is shown immediately, along with the full formula used. Use the gas bill calculator to convert kWh into pounds.
Every gas bill in the UK converts your meter reading — measured in cubic metres (m³) — into kilowatt hours (kWh) before calculating the cost. This conversion isn't arbitrary: it's mandated by Ofgem, the UK energy regulator, and every supplier from British Gas to Octopus Energy uses the same formula.
Gas meters measure the volume of gas passing through them — in cubic metres for modern metric meters, or cubic feet for older imperial meters. But gas is sold by its energy content, not its volume. A cubic metre of gas contains different amounts of energy depending on its composition, temperature, and pressure — which is why the calorific value and volume correction factor are applied before billing.
The full conversion formula is: kWh = m³ × Calorific Value × 1.02264 ÷ 3.6. Use our gas m3 to kWh calculator to apply this instantly, or our conversion guide for a detailed step-by-step walkthrough.
The calorific value (CV) measures how much energy is contained in one cubic metre of gas. In the UK, this typically ranges from 37.5 to 43.0 kWh/m³ and varies by region, season, and gas source. The UK average is approximately 39.5 kWh/m³. Your supplier is required to print your actual CV on your gas bill — look for it in the usage breakdown section. For the most accurate calculation, always use your bill's specific CV in our calculator.
According to Ofgem's consumption figures, a typical UK household uses around 11,500 kWh of gas per year (medium consumption). This is roughly 1,030 m³ annually, or about 86 m³ per month. Compare your usage with our gas usage calculator to see whether you're above or below the national average.
If your meter display shows ft³ or CF, you have an imperial meter — common in pre-1990s UK properties. The conversion is slightly different because cubic feet must first be converted to cubic metres (1 ft³ = 0.0283168 m³) before applying the standard formula. Our gas units to kWh calculator handles both types automatically — just select your meter type from the dropdown.
Based on UK standard calorific value of 39.5 kWh/m³ and VCF of 1.02264. See full 25-row table →
| Gas Used (m³) | Energy (kWh) | Approx Cost at 7.42p/kWh |
|---|---|---|
| 1 m³ | 11.18 kWh | £0.83 |
| 5 m³ | 55.92 kWh | £4.15 |
| 10 m³ | 111.84 kWh | £8.30 |
| 20 m³ | 223.68 kWh | £16.60 |
| 50 m³ | 559.20 kWh | £41.49 |
| 100 m³ | 1,118.39 kWh | £82.98 |
| 200 m³ | 2,236.79 kWh | £165.97 |
| 500 m³ | 5,591.97 kWh | £414.92 |
Formula: kWh = m³ × 39.5 × 1.02264 ÷ 3.6. Cost based on Ofgem Q1 2025 unit rate (7.42p/kWh). Use the gas bill calculator to enter your own rate.
Everything you need to know about converting UK gas units