Tons Of TNT to Calories (tTNT to cal)

1 ton of TNT equals 1,000,000,000 calories exactly.

1 ton of TNT = 1,000,000,000 calories

How to convert tons of TNT to calories

To convert tons of TNT to calories, multiply the number of tons of TNT by 1,000,000,000. This factor is exact. To go the other way, multiply calories by 1×10⁻⁹.

calories = tons of TNT × 1,000,000,000

Example: 10 tons of TNT = 10,000,000,000 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

Ton Of TNT (tTNT)

ScientificCurrent unit

Exactly 4.184 gigajoules by convention (one tonne of TNT). The unit for explosions; a megaton is a million of them.

Explosive yields are quoted against a reference charge, and the ton of TNT is the one that stuck. Real TNT does not release a single fixed amount of energy: measured values run near 4,686 joules per gram, calculations give about 4,853, and a large open blast can burn more of its products in air than a small one. To sidestep the argument, the energy of a gram of TNT was set by convention at 4,184 joules, one kilocalorie, so a ton is exactly 4.184 gigajoules.

That makes a kiloton 4.184 terajoules and a megaton 4.184 petajoules. The scale is mostly used for nuclear weapons and asteroid impacts. The Hiroshima bomb is usually put at about 15 kilotons (63 terajoules) and the Nagasaki bomb at about 20 kilotons (84 terajoules). NIST lists the ton of TNT at 4.184 x 10^9 joules as an exact factor, matching the convention used here.

1 ton of TNT = 4,184,000,000 joules (exactly).

Sources: Wikipedia: TNT equivalent; NIST SP 811, Appendix B.8

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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