Convert kilocalories to kilojoules
1 kcal = 4.184 kJ — exactly. Both units are defined against the SI, so this factor is a fraction, not an approximation.
4.184kJ
As a fraction: 523/125
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1 kcal = 4.184 kJ
Show this value in all 39 energy & work units
- Petajoules PJ 4.184e-12
- Terajoules TJ 4.184e-9
- Gigajoules GJ 0.000 004 184
- Megajoules MJ 0.004 184
- Kilojoules kJ 4.184
- Joules J 4184
- Millijoules mJ 4 184 000
- Microjoules µJ 4 184 000 000
- Nanojoules nJ 4 184 000 000 000
- Watt-hours Wh 1.162 222 222 22
- Kilowatt-hours kWh 0.001 162 222 222 22
- Megawatt-hours MWh 0.000 001 162 222 222 22
- Gigawatt-hours GWh 1.16222222222e-9
- Terawatt-hours TWh 1.16222222222e-12
- Calorie (thermochemical)s cal 1000
- Kilocalories kcal 1
- Calorie (IT)s cal (IT) 999.331 231 489
- Kilocalorie (IT)s kcal (IT) 0.999 331 231 489
- British thermal units BTU 3.965 666 831 39
- BTU (thermochemical)s BTU (th) 3.968 321 714 8
- Million BTUs MMBTU 0.000 003 965 666 831 39
- Therm (US)s thm 0.000 039 666 137 026 4
- Therm (EC)s thm (EC) 0.000 039 656 662 774 3
- Electronvolts eV 2.61144739675e+22
- Kiloelectronvolts keV 2.61144739675e+19
- Megaelectronvolts MeV 2.61144739675e+16
- Gigaelectronvolts GeV 26 114 473 967 500
- Teraelectronvolts TeV 26 114 473 967.5
- Ergs erg 41 840 000 000
- Foot-pounds ft·lbf 3085.960 032 58
- Inch-pounds in·lbf 37 031.520 390 9
- Foot-poundals ft·pdl 99 287.827 931 3
- Horsepower-hours hp·h 0.001 558 565 673 02
- Tonne of TNTs t TNT 0.000 001
- Kiloton of TNTs kt TNT 1e-9
- Megaton of TNTs Mt TNT 1e-12
- Hartrees Eₕ 9.59689217281e+20
- Rydbergs Ry 1.91937843456e+21
- Quads quad 3.96566683139e-15
Every row is Kilocalorie (kcal) converted through the joule, in exact rational arithmetic.
How to convert kilocalories to kilojoules
Multiply the number of kilocalories by 4.184 to get kilojoules.
The exact factor is 4.184 — as a fraction, 523/125.
Kilocalorie: The Calorie on food labels — 1000 small calories.
Kilocalorie to Kilojoule conversion table
| Kilocalories (kcal) | Kilojoules (kJ) |
|---|---|
| 1 kcal | 4.184 |
| 2 kcal | 8.368 |
| 3 kcal | 12.552 |
| 5 kcal | 20.92 |
| 10 kcal | 41.84 |
| 20 kcal | 83.68 |
| 25 kcal | 104.6 |
| 50 kcal | 209.2 |
| 100 kcal | 418.4 |
| 250 kcal | 1046 |
| 500 kcal | 2092 |
| 1000 kcal | 4184 |
Kilojoule to Kilocalorie conversion table
| Kilojoules (kJ) | Kilocalories (kcal) |
|---|---|
| 1 kJ | 0.239 005 74 |
| 2 kJ | 0.478 011 47 |
| 3 kJ | 0.717 017 21 |
| 5 kJ | 1.195 028 7 |
| 10 kJ | 2.390 057 4 |
| 20 kJ | 4.780 114 7 |
| 25 kJ | 5.975 143 4 |
| 50 kJ | 11.950 287 |
| 100 kJ | 23.900 574 |
| 250 kJ | 59.751 434 |
| 500 kJ | 119.502 87 |
| 1000 kJ | 239.005 74 |
Frequently asked
How many kilojoules are in a kilocalorie?
One kilocalorie equals 4.184 kilojoules (kcal → kJ). That figure is exact, not rounded.
How do you convert kilocalories to kilojoules?
Multiply the number of kilocalories by 4.184 to get kilojoules.
What is 1 kJ in kilocalories?
One kilojoule is 0.2390057361 kilocalories.
What is 10 kcal in kJ?
10 kcal = 41.84 kJ.
What exactly is a kilocalorie?
The Calorie on food labels — 1000 small calories.