A month of readings on a metric meter
The meter moved from 4,520 to 4,870, so 350 m³ was used. 350 × 1.02264 × 39.5 ÷ 3.6 = 3,927 kWh, or about 11.2 kWh for each cubic metre on the meter.
Gas energy, gross 3,927 kWh Open in the calculator
Gas m³ to kWh calculator
Convert gas meter readings in cubic metres or hundreds of cubic feet to kWh, the way a gas bill does.
You enterCalculated
Gasm³
Current reading
Previous reading
Used
- Volume correction factorTo 15 °C and 1013.25 mbar357.9
- Calorific valueGross, from the bill14,138
- Megajoules to kWh3.6 MJ per kWhExactly, by definition3,927
Each cubic metre through the meter is 11.22 kWh at this calorific value and correction.
Type the readings into the meter, or the factors from the bill. Press the volume used to enter a volume instead.
Gas energy, gross
3,927kWh
350 m³ at a calorific value of 39.5 MJ/m³.
Check the values to see a result.
- Volume used
- 350 m³
- Volume at 15 °C and 1013.25 mbar
- 357.9 m³
- Energy in megajoules
- 14,138 MJ
- Energy per cubic metre metered
- 11.22 kWh/m³
Gross calorific value, as bills state it. Net energy, which excludes the latent heat of the water vapour, is about 10% lower.
How it’s calculated
- Units = current − previous=4,870 − 4,520=350
- E = V × CF × CV ÷ 3.6=350 × 1.02264 × 39.5 ÷ 3.6=3,927 kWh
kWh = volume (m³) × correction factor × calorific value (MJ/m³) ÷ 3.6
350 m³ of gas at a calorific value of 39.5 MJ/m³ and a correction factor of 1.02264 is 3,927 kWh.
Tip: Use the calorific value printed on the bill for the same period. It changes from month to month by a few percent.
How to convert gas m³ to kWh
To convert gas from cubic metres to kWh, multiply the volume by the volume correction factor and the calorific value in MJ/m³, then divide by 3.6. 350 m³ at a calorific value of 39.5 MJ/m³ and the standard correction factor of 1.02264 is 3,927 kWh.
Gas is metered by volume but billed by energy. The calorific value, printed on every bill, says how much energy each cubic metre holds.
Metric meters (m³)
kWh = m³ × correction factor × calorific value ÷ 3.6
Subtract the previous reading from the current one to get the volume. The 3.6 converts megajoules to kWh, because 1 kWh is exactly 3.6 MJ.
Imperial meters (hundreds of cubic feet)
m³ = hundreds of ft3 × 2.832
An imperial meter counts in units of 100 cubic feet. Multiply the difference between readings by 2.832 to get cubic metres, then use the metric formula.
The correction factor
1.02264 for most supplies in Great Britain
A meter measures gas at the temperature and pressure in the pipe. The correction factor converts it to the standard 15 °C and 1013.25 mbar. The Gas (Calculation of Thermal Energy) Regulations 1996 fix it at 1.02264 for supplies not expected to exceed 732,000 kWh a year; larger supplies correct for their measured conditions.
Reading the meter
units used = current reading − previous reading
Read the digits from left to right and leave out any after the decimal point or shown in red. A metric meter is marked m³ and counts cubic metres. An imperial meter is marked ft³ or cu ft and counts hundreds of cubic feet. The difference between two readings is the units used, the figure a bill starts from.
A calorific value in kWh/m³
kWh = m³ × correction factor × calorific value (kWh/m³)
Some bills state the calorific value in kWh/m³ rather than MJ/m³. Then leave out the ÷ 3.6, or multiply by 3.6 to enter the value here: 11.2 kWh/m³ is 40.32 MJ/m³. Some bills multiply the correction factor and the calorific value into one conversion factor in kWh/m³; multiply the volume by it. A volume in standard cubic metres (Sm³) is already corrected, so its correction factor is 1.
The calorific value on a bill is gross, also called the higher heating value: it includes the heat recovered by condensing the water vapour in the flue gas. Boiler efficiencies are sometimes quoted on a net basis, which excludes it. For natural gas the net value is about 10% lower than the gross.
Gas m³ to kWh examples
An imperial meter
125 units of 100 cubic feet is 125 × 2.832 = 354 m³. At a calorific value of 39.2 MJ/m³ that is 3,941 kWh.
Gas energy, gross 3,941 kWh Open in the calculator
A large supply with its own correction factor
A site using well over 732,000 kWh a year has its correction factor calculated from the measured temperature and pressure. With 12,000 m³ at a factor of 1.0172 from the bill and 39.8 MJ/m³, the energy is 134,949 kWh.
Gas energy, gross 134,949 kWh Open in the calculator
Gas m³ to kWh table
Energy for common volumes at three calorific values, with the standard correction factor of 1.02264.
| Volume (m³) | 38.5 MJ/m³ (kWh) | 39.5 MJ/m³ (kWh) | 40.5 MJ/m³ (kWh) |
|---|---|---|---|
| 1 | 10.94 | 11.22 | 11.5 |
| 10 | 109.4 | 112.2 | 115 |
| 50 | 546.8 | 561 | 575.2 |
| 100 | 1,094 | 1,122 | 1,150 |
| 250 | 2,734 | 2,805 | 2,876 |
| 500 | 5,468 | 5,610 | 5,752 |
| 1,000 | 10,937 | 11,221 | 11,505 |
| 5,000 | 54,683 | 56,103 | 57,524 |
| 10,000 | 109,366 | 112,206 | 115,047 |
Questions about gas m³ to kWh
How many kWh are in 1 m³ of gas?
About 11.2 kWh at a calorific value of 39.5 MJ/m³ and the standard correction factor. The exact figure changes with the calorific value on each bill.
Where do I find the calorific value?
On the gas bill, usually beside the conversion from units to kWh. The gas transporter measures it and it changes slightly from day to day, so bills use an average for the period.
Why does my bill show a different kWh figure?
Check the correction factor and the calorific value against the bill, and whether the meter is metric or imperial. An imperial meter read as cubic metres gives an answer 2.8 times too low.
How do I turn gas kWh into carbon emissions?
Multiply by an emission factor for natural gas on a gross calorific value basis. The carbon emissions calculator uses the current UK DESNZ factor.
How do I convert gas units to kWh?
A unit is one step of the meter: 1 m³ on a metric meter, 100 cubic feet on an imperial one. On a metric meter, 100 units at 39.5 MJ/m³ and the standard correction factor are 1,122 kWh. On an imperial meter, 100 units are 283.2 m³, or 3,177 kWh. One cubic foot of gas is about 0.318 kWh.
How do I convert kWh to m³ of gas?
Divide the kWh by the kWh per cubic metre: m³ = kWh × 3.6 ÷ (correction factor × calorific value). At 39.5 MJ/m³ and 1.02264, each m³ is 11.22 kWh, so 1,000 kWh is 89.12 m³.
Limits of this result
- Large supplies correct for their actual temperature, pressure and compressibility instead of a fixed factor; use the factor on the bill.
- The calorific value is gross (higher heating value). Boiler efficiencies quoted on a net basis need converting.
- A meter reading that rolls over past its highest value must be entered as a volume.
Measure the energy behind the figure
Many gas meters have a pulse output. A ZPC counts it, so the kWh follow from each interval’s volume instead of a monthly reading. The ZPC is not Ex rated, so it goes outside any hazardous area.