Work out gas meter reading conversion instantly with clear inputs, formula shown and shareable results.
Gas meters measure volume, but gas is billed on energy. The metered volume is first converted to cubic metres, then adjusted by a volume correction factor for temperature and pressure, then multiplied by the calorific value of the gas supplied. Dividing megajoules by 3.6 gives kilowatt-hours.
Gas billing conversion
Energy (kWh) = volume (m3) x volume correction factor x calorific value (MJ/m3) / 3.6
It corrects metered volume to standard temperature and pressure. A typical UK figure is 1.02264 for a low-pressure domestic meter; correctors on industrial meters compute it live from measured conditions.
It depends on the gas actually delivered, which varies with supply source. Network operators publish a declared calorific value for each billing zone and period.