Meter readings to billed energy for UK, European, US and Indian networks — using the calorific value that was actually delivered, because nothing else can do the job.
Calculator
Typical:
The calorific value is an input, not a constant. On this network it typically runs 38–41 MJ/m³, and the exact figure for the period you are billing for is printed on the bill. The calorific value used is printed on the bill and changes month to month. Older meters read in hundreds of cubic feet.
100 m³ at 39.5 MJ/m³
1,122.1 kWh
38.286 therms · 4,039.4 MJ · after the volume correction 1.02264
The same energy in every billing unit
Energy units, ordered by size — all exactly defined
Unit
Value
Where you meet it
British thermal unit (BTU)
3,828,639.0
The international-table BTU. Other definitions differ by up to 0.2%.
kilocalorie (kcal)
964,800.8
The international-table kilocalorie. Indian gross calorific values are quoted per SCM in these.
megajoule (MJ)
4,039.4
The SI unit calorific values are published in.
kilowatt-hour (kWh)
1,122.1
Exactly 3.6 MJ. What a UK or EU gas bill charges in.
therm (thm)
38.286
Exactly 100 000 BTU, or 29.3071 kWh. What a US gas bill charges in.
gigajoule (GJ)
4.039
Canadian and industrial billing.
million BTU (MMBtu)
3.829
Ten therms. The wholesale gas contract unit worldwide.
Every conversion in this table is exact, because every unit in it is defined in joules. The step that is not exact is the one above it — turning 102.264 m³ of gas into 4,039.4 MJ needed the calorific value, and that is a measurement of a particular gas in a particular month.
Gross energy, net energy, and boiler efficiency
Gross (higher heating value)1,122.1 kWhwhat the bill charges for
Net (lower heating value)1,011.8 kWhwhat net-basis efficiencies refer to
The gap9.8%energy carried away as water vapour
Burning gas makes water, and the heat used to vaporise it is only recovered if the flue gas is condensed. Gross calorific value counts that heat, net does not, and they differ by about a tenth. This is why boilers get advertised at “up to 98% efficient” on a net basis while delivering something closer to 88% of the energy the bill charged for — the two numbers are not in disagreement, they are answering different questions.
What “multiply by 11.2” assumes
Your multiplier11.22061.02264 × 39.5 ÷ 3.6
The copied shortcut11.2000-0.184% against yours
Exact at a calorific value of39.43 MJ/m³and nowhere else on this network
The shortcut is not wrong so much as frozen. It has one calorific value and one correction factor baked into a single number, so it silently stops being right when either changes — and both change. On a UK bill the correction is fixed at 1.02264, but the calorific value is reprinted every billing period.
If the meter is an imperial one
Read as hundreds of cubic feet283.168 m³correct for an imperial dial
Read as cubic metres100.000 m³35.3% of the real volume
Older UK meters count in hundreds of cubic feet, and the dials look much like a metric meter’s. Treating one reading as the other loses nearly two thirds of the gas, and the resulting bill still looks plausible, which is what makes it worth checking once. A metric meter is usually marked m³ near the dials; an imperial one is marked ft³ or 100 ft³.
At your own unit rate
Energy charge67.321,122.1 kWh × 0.06
A 14.2 kg LPG cylinder, for comparison195.644 kWha different fuel, sold by mass
No tariff is assumed anywhere here — the rate is yours, and no standing charge is included, because that is a daily charge rather than a charge on gas. The cylinder line is an energy comparison, not a conversion: LPG is propane and butane rather than methane, it is sold by weight, and its calorific value per kilogram has nothing to do with the per-cubic-metre figure above. Indian bills publish the same calorific value as 9,434 kcal per SCM.
How the networks differ
Delivered gas and billing practice, by region
Network
Typical CV
Range
Correction
Meter → bill
United Kingdom & Ireland
39.5 MJ/m³
38–41
volume correction 1.02264
m³ → kWh
Continental Europe — H-gas
40 MJ/m³
38.5–42.5
state number (Zustandszahl) ≈ 0.95
m³ → kWh
Netherlands & north-west Germany — L-gas
35.2 MJ/m³
33.3–36
state number (Zustandszahl) ≈ 0.95
m³ → kWh
United States & Canada
38.6 MJ/m³
37.3–41
pressure factor, usually 1.00 at domestic pressure
ccf → thm
India — piped natural gas
37.7 MJ/m³
36–40.2
none shown on a domestic bill
m³ → kWh
The two European rows are the same continent and differ by about 12% per cubic metre, because Groningen-type L-gas genuinely carries less energy than the H-gas piped everywhere else. That is why the two networks are not interchangeable and why appliances had to be converted when the Netherlands wound Groningen down.
What this converter covers
Cubic metres, cubic feet, ccf and Mcf into kWh, therms, MJ and MMBtu — with the correction factor, the gross-to-net gap and the imperial-meter trap all shown.
Meter volume to billed energy for UK, EU H-gas and L-gas, US and Indian networks
The volume correction factor, and the German state number that runs the other way
What the copied “multiply by 11.2” shortcut actually assumes
Imperial meters that count hundreds of cubic feet
Gross against net calorific value, and boiler efficiency claims
Calorific value is an input Correction factor included Gross vs net kWh · therms · MJ · MMBtu
Free, no signup — exact by definition, not an estimate.
Updated 8 September 2026
At a glance
Formula shown
kWh = volume in m³ × correction factor × calorific value in MJ/m³ ÷ 3.6
Scenario support
100 m³ at 39.5 MJ/m³ in the UK is 1,122 kWh · 100 ccf at 38.6 MJ/m³ in the US is 103.6 therms
Educational estimate
Planning support from the values you enter — not professional advice.
Volume is not energy
A gas meter counts cubic metres. A gas bill charges kilowatt-hours. Almost everything written about the gap between the two describes it as a conversion, and it is not one.
There is no factor between volume and energy the way there is between metres and feet. What bridges them is the calorific value of the gas that was actually delivered — how much energy is in a cubic metre of it — and that is a measured property of a particular gas mixture flowing through a particular network in a particular month.
So this page asks for it. Leave the field empty and nothing is returned, because nothing honest can be. That refusal is the whole point: a meter reading on its own simply does not contain the answer.
How much it moves is easy to under-rate. Gas piped into the Netherlands and north-west Germany is Groningen-type L-gas at around 35 MJ/m³. The H-gas piped almost everywhere else is around 40. Same reading, same meter, roughly 12% more energy — which is exactly why appliances had to be physically converted when the Netherlands wound Groningen down, rather than simply re-billed.
The factor before the factor
Before the calorific value is applied at all, the metered volume is corrected.
A meter measures the gas at whatever temperature and pressure it happens to be at when it passes through, and gas expands. Billing needs a volume at agreed standard conditions, so the reading is multiplied by a correction factor first.
The correction step, by network
Network
Correction
Direction
United Kingdom & Ireland
1.02264, statutory
Raises the volume 2.3%
Germany
Zustandszahl, typically 0.90–0.98
Usually lowers it
United States
Pressure factor, near 1.00 domestically
Usually no visible effect
India — PNG
None on a domestic bill
Billed per SCM directly
The UK factor is fixed in law at 1.02264 and appears on every bill. The German state number is not fixed at all — it depends on the altitude of the property and the pressure the meter runs at, so the supplier calculates one for the address, and it usually sits below one.
Two networks, two factors, pointing in opposite directions. Anyone carrying a remembered multiplier across a border has it backwards by roughly seven per cent before the calorific value is even considered.
Why 11.2 keeps drifting
The most repeated piece of advice on this subject is that you multiply cubic metres by 11.2 to get kilowatt-hours. It is a genuinely useful number and it is exactly right under one set of conditions.
Those conditions are visible if the shortcut is taken apart:
11.2 is 1.02264 × 39.5 ÷ 3.6. The 1.02264 is the UK volume correction, the 39.5 is one particular calorific value in MJ/m³, and the 3.6 is the exact number of megajoules in a kilowatt-hour.
Only one of those three is a constant. The correction factor is fixed by regulation, so it will not move. The 3.6 is a definition. But 39.5 is a reading, republished every billing period, and typically anywhere from 38 to 41 depending on where the gas came from.
Which means the shortcut does not fail loudly — it drifts. A bill computed with 11.2 against gas actually delivered at 40.5 MJ/m³ comes out about 2.5% low, and nothing about the answer looks wrong. The calculator above shows the multiplier your own calorific value implies, and how far 11.2 is from it.
The meter that reads in feet
This one is rarer and much larger, and it is worth thirty seconds at the meter cupboard.
A good number of UK homes still have an imperial gas meter. Its dials do not count cubic metres — they count hundreds of cubic feet, and they look very much like the metric ones.
A hundred cubic feet is 2.83 cubic metres. Reading an imperial dial as though it were metric therefore records about 35% of the gas that actually passed through it, and the resulting figure is not absurd enough to catch the eye. It reads like a slightly light bill.
The tell is printed on the meter itself. A metric meter is marked m³ near the dials; an imperial one is marked ft³ or 100 ft³. If a submitted reading has ever produced a bill that looked oddly low and was later corrected upwards, this is usually why.
Gross, net, and the 98% boiler
There is one more place where two numbers describe the same gas and disagree by about a tenth.
Burning natural gas produces water vapour, and vaporising that water absorbs energy. Gross calorific value — also called the higher heating value — counts that energy, on the basis that a condensing appliance can recover it. Net, or lower heating value, does not.
For pipeline natural gas the ratio is close to 1.11, so the two figures differ by roughly 10%. Gas bills, everywhere that matters, charge on the gross figure.
Boiler efficiencies, meanwhile, are traditionally quoted on the net basis. That is how a boiler can honestly be advertised at “up to 98% efficient”. Against the gross energy the bill charged for, the same appliance is delivering something closer to 88%.
Neither number is dishonest, and comparing them directly is the mistake. If you are working out what a heating upgrade saves, take the efficiencies from the same basis — and if one of them came off a gas bill, that basis is gross.
Related calculators
Other energy, power and building tools:
EnergyJoules, kilojoules, calories, food Calories, kWh, BTU and therms — with the two calories listed apart, since one is a thousand of the other.
PowerWatts, kilowatts, horsepower and BTU per hour — with mechanical and metric horsepower listed apart, since they differ by 1.4% under one word.
VolumeLitres, gallons, pints and cubic units — with US and imperial named apart, because a UK gallon is 20% larger than a US one.
Tons to BTUAC capacity in tons, BTU/h and kW — with the electricity a unit actually draws, which is three to five times smaller than its rating.
Watts to AmpsWatts, amps and volts at UK, EU, India and US supplies — single or three phase, with volt-amps beside the watts.
R-ValueR-value, RSI, U-value and lambda — with the thickness each material needs, and the third of an insulation spec that framing quietly takes back.
Two of these define the arithmetic and two supply the numbers that are not definitional. The UK regulations give the statutory formula and the correction factor; the SI Brochure is why every step after the calorific value is exact; and the EIA and the UK conversion factors are where the typical calorific values and the gross-to-net gap come from.
The Gas (Calculation of Thermal Energy) Regulations 1996UK Statutory Instruments · verified 2026-09-08 · The statutory UK formula for turning a metered gas volume into billed energy, including the volume correction factor of 1.02264 and the requirement that the calorific value used be the one determined for that gas in that period
Frequently Asked Questions — the heat content of natural gas delivered to consumersU.S. Energy Information Administration · verified 2026-09-08 · The representative US heat content of delivered natural gas near 1035 BTU per cubic foot, and the fact that it varies, which is why a US bill converts ccf to therms with a heating-value factor rather than one to one
Government conversion factors for company reporting of greenhouse gas emissionsUK Department for Energy Security and Net Zero · verified 2026-09-08 · Published gross and net calorific values for natural gas side by side, which is the basis for the roughly one-tenth gap between the energy a bill charges for and the energy a net-basis appliance efficiency refers to
SI Brochure, 9th editionBureau International des Poids et Mesures · verified 2026-09-08 · That the kilowatt-hour is exactly 3.6 megajoules and the joule is the SI unit of energy, which is what makes every conversion in the energy table exact and isolates the calorific value as the only inexact step
Conversion note
This converts units and applies the formula your network uses; it does not reproduce your bill. The calorific value on a real bill is set for a specific gas, in a specific place, over a specific period, and the typical figures offered here are published averages with genuine spread — use the value printed on your own statement whenever you have it. Correction factors vary too: the UK factor is statutory and fixed, but the German state number depends on your altitude and meter pressure and your supplier calculates it for your address. Nothing here includes standing charges, taxes, VAT or GST, regional levies, tiered or block tariffs, or supplier rounding rules, all of which change the amount payable. Prepayment meters, commercial contracts and estimated readings each add their own arithmetic. The LPG comparison is an energy comparison between two different fuels, not a conversion, and the cylinder figure is a nominal calorific value rather than the contents of any particular cylinder. If a bill looks wrong, the meter reading, the correction factor and the calorific value are three separate things to check, and your supplier can confirm all three.
Published the Gas m³ to kWh Converter: cubic metres, cubic feet, hundreds of cubic feet and thousands of cubic feet into kilowatt-hours, therms, megajoules, gigajoules and million BTU, for UK, continental European, US and Indian networks.
Treats the calorific value as an INPUT rather than a constant, and refuses to return anything without one, because a gas meter measures volume, a gas bill charges energy, and no factor connects the two on its own.
Carries five published network profiles with the range each calorific value actually moves in, and states that the exact figure for a billing period is printed on the bill.
Applies the correction step before the calorific value, and shows that it points in opposite directions on different networks: the UK factor is fixed in law at 1.02264 and raises the volume, while the German Zustandszahl depends on altitude and meter pressure and usually lowers it.
Takes apart the most copied shortcut on the subject. Multiplying cubic metres by 11.2 is 1.02264 times 39.5 divided by 3.6, so it silently freezes one calorific value into a single number; the page computes the multiplier the user's own value implies and the calorific value at which 11.2 would be exact.
Warns about imperial gas meters, which count hundreds of cubic FEET on dials that resemble metric ones -- reading one as cubic metres records about 35 per cent of the gas that passed through, on a bill that still looks plausible.
Separates gross from net calorific value, which differ by about a tenth for pipeline natural gas: bills charge on gross while boiler efficiencies are traditionally quoted on net, which is how a boiler is honestly advertised at 98 per cent while delivering nearer 88 per cent of the energy billed.
Compares a 14.2 kg LPG cylinder as ENERGY rather than converting it, because LPG is a different fuel sold by mass and no unit conversion exists between kilograms of it and cubic metres of natural gas.
Assumes no tariff anywhere: the unit rate is the user's own, no standing charge is applied, and no currency is named.
Verified by 82 automated cases, asserting that the bridge refuses a zero, negative, missing or non-finite calorific value while still returning zero energy for a zero reading, that volume-to-energy and energy-to-volume invert each other through the correction factor, that the 11.2 shortcut is exact at exactly one calorific value and signed correctly either side of it, and that every network's typical value lies inside its own published range.
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