Tonnes Of Oil Equivalent to Calories (toe to cal)

1 tonne of oil equivalent equals 10,006,692,161 calories (rounded).

1 tonne of oil equivalent = 10,006,692,161 calories

How to convert tonnes of oil equivalent to calories

To convert tonnes of oil equivalent to calories, multiply the number of tonnes of oil equivalent by 10,006,692,161. The factor is rounded to 10 significant digits. To go the other way, multiply calories by 9.993312315×10⁻¹¹ (rounded).

calories = tonnes of oil equivalent × 10,006,692,161

Example: 10 tonnes of oil equivalent = 100,066,921,606 calories.

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

About these units

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

Calorie (cal)

ScientificTraditional unit (still used in some regions)

The thermochemical calorie: exactly 4.184 joules, the energy to raise one gram of water by one degree Celsius. Not the same as the food Calorie, which is a kilocalorie.

Latin calor, meaning heat, supplied the name. Nicolas Clement used it in lectures on heat engines between 1819 and 1824, and by 1852 Pierre Favre and Jean Silbermann applied it to the small unit based on a single gram of water warmed by one degree Celsius. Because the specific heat of water varies slightly with temperature, early calories differed from one laboratory to the next. A mean value near 4.1855 J was published for the 15 degree calorie in 1950, with an uncertainty of 0.0005 J.

Chemists settled the matter by definition. The thermochemical calorie is exactly 4.184 J, which is the figure used here, and NIST lists it with that exact value. The calorie is not an SI unit and is regarded as obsolete, since the ninth General Conference on Weights and Measures in 1948 preferred the joule for heat. One thousand of these calories make a kilocalorie, the larger unit used for food, and a slightly larger calorie, the International Table version of 4.1868 J, is used in steam tables.

1 calorie = 4.184 joules (exactly).

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

Related conversions

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