Kilocalories to Tonnes Of Oil Equivalent (kcal to toe)

1 kilocalorie equals 9.993312315×10⁻⁸ tonnes of oil equivalent (rounded).

1 kilocalorie = 9.993312315×10⁻⁸ tonnes of oil equivalent

How to convert kilocalories to tonnes of oil equivalent

To convert kilocalories to tonnes of oil equivalent, multiply the number of kilocalories by 9.993312315×10⁻⁸. The factor is rounded to 10 significant digits. To go the other way, multiply tonnes of oil equivalent by 10,006,692.16 (rounded).

tonnes of oil equivalent = kilocalories × 9.993312315×10⁻⁸

Example: 10 kilocalories = 9.993312315×10⁻⁷ tonnes of oil equivalent.

The 'calorie' on food labels is really a kilocalorie. The thermochemical calorie (4.184 J) is used here unless marked IT.

About these units

Kilocalorie (kcal)

ScientificTraditional unit (still used in some regions)

1,000 thermochemical calories (4,184 J). The 'Calorie' on food labels in North America.

Marcellin Berthelot separated the gram calorie from the kilogram calorie in 1879, and the American chemist Wilbur Atwater adopted a capital-C Calorie for the large unit in 1887 in a widely read article on the energy in food. Joseph Howard Raymond proposed the term kilocalorie in his 1894 textbook. The two names now describe the same quantity, 1,000 small calories, which at the thermochemical value is 4,184 J or 4.184 kJ.

Food labels carry the unit today, though practice differs by region. North American labels use kilocalories almost exclusively, European labels show kilojoules and kilocalories together under EU Regulation 1169/2011, and Chinese labels give kilojoules only. Typical energy contents are about 9 kcal per gram for fat, about 4 for carbohydrate and protein, and about 7 for alcohol. In electrical terms, 4,184 J works out to about 1.162 watt-hours, since one watt-hour is 3,600 J. NIST also lists a kilocalorie based on the International Table calorie, which is 4,186.8 J.

1 kilocalorie = 4,184 joules (exactly).

Sources: Wikipedia: Calorie (includes kilocalorie); NIST SP 811, Appendix B.8 (energy conversion factors)

Tonne Of Oil Equivalent (toe)

Metric (SI)Current unit

Exactly 41.868 GJ, the energy released by burning one tonne of crude oil. A standard unit in energy statistics.

Energy statisticians need a way to add up coal, gas, hydro and oil in one column, and the tonne of oil equivalent does that by expressing everything as the heat from burning a tonne of crude oil. Because crude oils differ in calorific value, the figure is a convention rather than a measurement, and more than one version circulates. The International Energy Agency uses 41.868 gigajoules, which is the figure used here. Other sources use 41.85 gigajoules, and a version based on the thermochemical calorie gives 44.769.

In everyday terms the IEA value is 11,630 kilowatt-hours, or about 39.7 million British thermal units, and it equals 10 gigacalories on the international steam table calorie. Smaller and larger steps are the kilogram of oil equivalent (one thousandth) and the megatoe and gigatoe. One toe is about 7.33 barrels of oil equivalent and 1.42857 tonnes of coal equivalent. Converting electricity into toe depends on an assumed plant efficiency, so national tables can differ.

1 tonne of oil equivalent = 41,868,000,000 joules (exactly).

Sources: Wikipedia: Tonne of oil equivalent; Wikipedia: Calorie

Related conversions

See all energy units.