Convert Kilojoules to Calories
1 kilojoule (kJ) equals 239.0057361 calories (cal).
1 kJ = 239.0057361 cal
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk kilojoule to calorie converter to paste a column from Excel.
How to Convert Kilojoule to Calorie
- 1 kJ = 239.0057361 cal
- 1 cal = 0.004184 kJ
- Example: convert 15 kJ to cal: 15 kJ = 15 × 239.0057361 cal = 3585.086042 cal
Reference conditions. cal: Thermochemical calorie, 4.184 J exactly. The International Table calorie is 4.1868 J.
Formula
cal = kJ × 239.0057361377
Derivation from SI units:
- 1 kJ = 10³ J
- 1 cal (thermochemical) = 4.184 J (exact)
- 1 kJ = 1000 J ÷ 4.184 J per cal = 239.0057361377 cal
Both units are defined exactly, so the factor is exact. Kilojoule definition: kilojoule; Calorie definition: calorie.
Worked examples
- A reading of 100 kJ converts to 23900.57361 cal.
100 kJ × 239.0057361 = 23900.57361 cal - A value of 1000 kJ is 239005.7361 cal.
1000 kJ × 239.0057361 = 239005.7361 cal
Kilojoule to Calorie conversion table
| Kilojoules (kJ) | Calories (cal) |
|---|---|
| 1 kJ | 239.0057361 cal |
| 4.184 kJ | 1000 cal |
| 10 kJ | 2390.057361 cal |
| 50 kJ | 11950.28681 cal |
| 100 kJ | 23900.57361 cal |
| 250 kJ | 59751.43403 cal |
| 500 kJ | 119502.8681 cal |
| 840 kJ | 200764.8184 cal |
| 1000 kJ | 239005.7361 cal |
| 2000 kJ | 478011.4723 cal |
| 8700 kJ | 2079349.904 cal |
| 10000 kJ | 2390057.361 cal |
Where it's used
Kilojoules are used for nutrition labels (kJ per serving), while calories appear in chemistry and calorimetry. Both measure energy, work and heat, so the conversion is a fixed factor.
Kilojoule to other energy units
| Conversion | 1 kJ equals |
|---|---|
| kilojoule to joule | 1000 J |
| kilojoule to megajoule | 0.001 MJ |
| kilojoule to calorie | 239.0057361 cal |
| kilojoule to kilocalorie | 0.2390057361 kcal |
| kilojoule to watt-hour | 0.2777777778 Wh |
| kilojoule to kilowatt-hour | 0.0002777777778 kWh |
| kilojoule to BTU | 0.9478171203 BTU |
| kilojoule to therm | 0.00000948043428 thm |
| kilojoule to electronvolt | 6.241509074 × 10²¹ eV |
| kilojoule to foot-pound | 737.5621493 ft·lbf |
| kilojoule to erg | 10000000000 erg |
Frequently asked questions
How many calories are in 1 kilojoule?
1 kJ = 239.0057361 cal.
How do I convert kilojoules to calories?
Multiply the value in kJ by 239.0057361. For example, 15 kJ × 239.0057361 = 3585.086042 cal.
Is the kJ to cal conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "calorie (thermochemical) (cal_th)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Kilojoules to Calories. Retrieved October 17, 2026, from https://scientificconverters.com/energy/kilojoules-to-calories/
IEEE
Scientific Converters, "Convert Kilojoules to Calories," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/kilojoules-to-calories/