Kilojoules to Megaelectronvolts (kJ to MeV)

1 kilojoule equals 6.241509074×10¹⁵ megaelectronvolts (rounded).

1 kilojoule = 6.241509074×10¹⁵ megaelectronvolts

How to convert kilojoules to megaelectronvolts

To convert kilojoules to megaelectronvolts, multiply the number of kilojoules by 6.241509074×10¹⁵. The factor is rounded to 10 significant digits. To go the other way, multiply megaelectronvolts by 1.602176634×10⁻¹⁶.

megaelectronvolts = kilojoules × 6.241509074×10¹⁵

Example: 10 kilojoules = 6.241509074×10¹⁶ megaelectronvolts.

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

About these units

Kilojoule (kJ)

Metric (SI)Current unit

1,000 joules. Food labels in many countries give energy in kilojoules.

Most food labels around the world express energy in kilojoules, which is the calorie's long retirement in action. The calorie came out of heat measurement, and the 1948 CGPM resolution stated that the joule should be preferred as the unit of heat. Labels that still show kilocalories alongside kilojoules rely on the thermochemical calorie of exactly 4.184 joules, so one kilocalorie is about 4.184 kJ.

The kilojoule is a convenient size for a body's daily bookkeeping. A person at rest uses about 5,000 kJ, or roughly 1,200 kcal, per day, and the recommended intake for a moderately active woman is given as 2,000 food calories, which is about 8,400 kJ.

Smaller physical comparisons land in the same range. One watt-hour is 3.6 kJ, a British thermal unit is about 1.1 kJ, exploding a gram of TNT releases about 4.2 kJ, and an alkaline AA battery holds about 9 kJ.

1 kilojoule = 1,000 joules (exactly).

Sources: Wikipedia: Kilojoule; Wikipedia: Joule; Wikipedia: Orders of magnitude (energy)

Megaelectronvolt (MeV)

ScientificCurrent unit

One million electronvolts. The scale of nuclear reactions.

Nuclei trade energy in millions of electronvolts. In binding-energy tables, medium-mass nuclei hold about 8.8 MeV per nucleon, with iron-56 listed at 8.7906 MeV. Fusing deuterium with tritium releases about 17.53 MeV per reaction, while an electron and positron annihilating give 1.022 MeV. One megaelectronvolt equals 1.602176634 x 10^-13 J, so even these reactions involve only tiny amounts of energy per event.

Per atom, though, the scale is enormous. A 17.53 MeV reaction is more than a million times the 1 to 10 eV that binds atoms into molecules, which is why nuclear fuels hold so much more energy than chemical ones. The electron's rest energy is 0.511 MeV and the muon's is 105.7 MeV, so the unit also serves for particle masses. A thousand MeV make one GeV, the next step up.

1 megaelectronvolt = 1.602176634×10⁻¹³ joules (exactly).

Sources: Wikipedia: Nuclear binding energy; Wikipedia: Electronvolt

Related conversions

See all energy units.