Convert billion m³ natural gas to kilojoule

The calorie of food labels is really the kilocalorie: 1 kcal = 1,000 cal = 4.1868 kJ, the heat that warms a kilogram of water by one degree. Nutrition labels in the EU must give both kJ and kcal, the US gives 'Calories' with a capital C meaning kcal, and the adult reference intake is 2,000 kcal, about 8,400 kJ. A slice of bread is around 80 kcal, an hour's brisk walk burns about 300.

Energy statistics reduce every fuel to a common yardstick. The tonne of oil equivalent is defined by the IEA as 41.868 GJ (11.63 MWh), roughly the energy in a tonne of crude; national energy balances are in Mtoe. The barrel of oil equivalent is used by oil companies, and its exact value varies between them, so figures are approximate. The tonne of coal equivalent is 29.3 GJ (7 million kcal), which Germany writes as SKE (Steinkohleeinheit). Natural gas is counted by volume or, as LNG, by mass: a billion cubic metres of gas is about 0.9 Mtoe.