A kilocalorie is 1,000 calories.
Kilocalories to Terajoules Converter — kcal to TJ
Convert Kilocalorie (kcal) to Terajoule (TJ) using the exact conversion factor (1 kilocalorie = 4.184e-9 terajoule). See the formula, worked examples, and conversion table.
Kilocalories to Terajoules converter
Converter
Energy Converter
Convert joules, calories, kilowatt-hours, BTU, electronvolts, therms, and mechanical work units.
Context values
Some unit families need one extra value for a physically accurate result.
Terajoule is 1000000000000 joule units.
Result = input x 4184 / 1e+12.
Energy uses the joule as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Kilocalories to Terajoules
Kilocalorie and Terajoule both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). Specifically: A kilocalorie is 1,000 calories, and terajoule is 1000000000000 joule units.
Formula
terajoules = kilocalories × 4.184e-9
This factor comes from each unit's defined relationship to the category's base unit: 1 kilocalorie equals 4184 base units, and 1 terajoule equals 1e+12 base units, so dividing one by the other gives the direct kilocalorie-to-terajoule factor of 4.184e-9.
Simple example
1 kcal × 4.184e-9 = 4.184e-9 TJ
1 kilocalorie = 4.184e-9 terajoules.
Real-world example
100 kcal × 4.184e-9 = 4.184e-7 TJ
100 kilocalories = 4.184e-7 terajoules.
Conversion table
| Kilocalorie (kcal) | Terajoule (TJ) |
|---|---|
| 1 kcal | 4.184e-9 TJ |
| 10 kcal | 4.184e-8 TJ |
| 100 kcal | 4.184e-7 TJ |
| 500 kcal | 0.000002092 TJ |
| 1,000 kcal | 0.000004184 TJ |
| 2,000 kcal | 0.000008368 TJ |
Reverse conversion: Terajoule to Kilocalorie
4.184e-9 TJ × 239005736.1 = 1 kcal
4.184e-9 terajoules = 1 kilocalorie.
kilocalories = terajoules × 239005736.138
For a page dedicated to this direction, see Terajoule to Kilocalorie.
Understanding the Kilocalorie (kcal)
A kilocalorie is 1,000 calories.
Understanding the Terajoule (TJ)
Terajoule is 1000000000000 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many terajoules are in 1 kilocalorie?
1 kilocalorie equals 4.184e-9 terajoules, using the exact defined conversion factor rather than an estimate.
How do I convert kilocalorie to terajoule?
Multiply the kilocalorie value by 4.184e-9. The converter above does this instantly to whatever precision you set.
How do I convert terajoule back to kilocalorie?
Use the reverse factor: 1 terajoule equals 239,005,736.1 kilocalories. You can also use the swap control in the converter above to flip the direction instantly.
What is a kilocalorie?
Kilocalorie (kcal) is a unit of energy.
What is a terajoule?
Terajoule (TJ) is a unit of energy.
Is the kilocalorie to terajoule conversion exact?
Yes. Both kilocalorie and terajoule are defined by fixed standards rather than physical artifacts, so the factor of 4.184e-9 used above is exact to as many digits as you choose to display.