Kilojoule (kJ)
A kilojoule is one thousand joules — the metric counterpart to the kilocalorie on food labels.
Kilojoules appear on Australian and European nutrition labels alongside or instead of kilocalories.
Kilojoule to Joule
Convert kilojoule to joule instantly. Type in either field — results update live.
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Energy Kilojoule Joule
1 kilojoule = 1,000 joules
Unit
Unit
Conversion table
Selected kJ values converted to J using the exact factor from this tool.
| kJ | J |
|---|---|
| 0.01 | 10 |
| 0.1 | 100 |
| 1 | 1,000 |
| 2 | 2,000 |
| 3 | 3,000 |
| 5 | 5,000 |
| 10 | 10,000 |
| 20 | 20,000 |
| 50 | 50,000 |
| 100 | 100,000 |
| 1,000 | 1,000,000 |
How to convert
Exact conversion factors in both directions, plus a worked example.
1 kJ = 1000 J
1 J = 0.001 kJ
To convert kilojoule to joule, multiply by 1000.
To convert joule to kilojoule, multiply by 0.001.
Example: convert 10 kJ to J
10 × 1000 = 10000 J
About these units
Short background on the units used in this conversion.
Joule (J)
The joule is the SI unit of energy — the work done when one newton moves an object one meter.
Joules quantify electricity bills (as kWh), food energy (as kcal), and scientific energy transfers.
Frequently asked questions
How many joules are in one kilojoule?
One kilojoule equals 1,000 joules. Multiply your kilojoules value by 1,000 to convert to joules.
What is the conversion formula?
J = kJ × 1,000The reverse is
kJ = J × 0.001, using the same exact factors as this converter.Is this Kilojoule to Joule converter private?
Yes. All calculations run locally in your browser. Nothing you type is sent to a server.
All kilojoule conversions
Jump to any energy conversion starting from kilojoule — including the reverse direction and every other unit in our dataset.
joule (J) → kilojoule (kJ)
kilojoule (kJ) → megajoule (MJ)kilojoule (kJ) → gigajoule (GJ)kilojoule (kJ) → kilowatt-hour (kW·h)kilojoule (kJ) → watt-hour (W·h)kilojoule (kJ) → calorie (nutritional / food calorie) (Cal)kilojoule (kJ) → kilocalorie (it) (kcal (IT))kilojoule (kJ) → kilocalorie (thermochemical) (kcal (th))kilojoule (kJ) → calorie (it) (cal (IT))kilojoule (kJ) → calorie (thermochemical) (cal (th))kilojoule (kJ) → british thermal unit (it) (Btu (IT))kilojoule (kJ) → british thermal unit (thermochemical) (Btu (th))kilojoule (kJ) → foot-pound (ft·lbf)kilojoule (kJ) → newton meter (N·m)kilojoule (kJ) → horsepower hour (mechanical) (hp·h)kilojoule (kJ) → horsepower (metric) hour (metric hp·h)kilojoule (kJ) → millijoule (mJ)kilojoule (kJ) → microjoule (µJ)kilojoule (kJ) → nanojoule (nJ)kilojoule (kJ) → attojoule (aJ)kilojoule (kJ) → megaelectron-volt (MeV)kilojoule (kJ) → kiloelectron-volt (keV)kilojoule (kJ) → electron-volt (eV)kilojoule (kJ) → ergkilojoule (kJ) → gigawatt-hour (GW·h)kilojoule (kJ) → megawatt-hour (MW·h)kilojoule (kJ) → kilowatt-second (kW·s)kilojoule (kJ) → watt-second (W·s)kilojoule (kJ) → mega british thermal unit (it) (MBtu (IT))kilojoule (kJ) → ton-hour (refrigeration) (ton·h)kilojoule (kJ) → fuel oil equivalent @ kiloliter (kL oil eq)kilojoule (kJ) → fuel oil equivalent @ barrel (us) (bbl oil eq)kilojoule (kJ) → gigaton (tnt) (Gton)kilojoule (kJ) → megaton (tnt) (Mton)kilojoule (kJ) → kiloton (tnt) (kton)kilojoule (kJ) → ton (explosives / tnt) (ton TNT)kilojoule (kJ) → dyne centimeter (dyn·cm)kilojoule (kJ) → gram-force meter (gf·m)kilojoule (kJ) → gram-force centimeter (gf·cm)kilojoule (kJ) → kilogram-force centimeter (kgf·cm)kilojoule (kJ) → kilogram-force meter (kgf·m)kilojoule (kJ) → kilopond meter (kp·m)kilojoule (kJ) → pound-force foot (lbf·ft)kilojoule (kJ) → pound-force inch (lbf·in)kilojoule (kJ) → ounce-force inch (ozf·in)kilojoule (kJ) → inch-pound (in·lbf)kilojoule (kJ) → inch-ounce (in·ozf)kilojoule (kJ) → poundal foot (pdl·ft)kilojoule (kJ) → thermkilojoule (kJ) → therm (ec)kilojoule (kJ) → therm (us)kilojoule (kJ) → hartree energy (Eh)kilojoule (kJ) → rydberg constant (Ry)