Convert Joules to Calories
1 joule (J) equals 0.2390057361 calories (cal).
1 J = 0.2390057361 cal
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk joule to calorie converter to paste a column from Excel.
How to Convert Joule to Calorie
- 1 J = 0.2390057361 cal
- 1 cal = 4.184 J
- Example: convert 15 J to cal: 15 J = 15 × 0.2390057361 cal = 3.585086042 cal
Reference conditions. cal: Thermochemical calorie, 4.184 J exactly. The International Table calorie is 4.1868 J.
Formula
cal = J × 0.2390057361377
or cal = J ÷ 4.184
Derivation from SI units:
- 1 J = 1 N·m = 1 W·s = 1 kg·m²·s⁻²
- 1 cal (thermochemical) = 4.184 J (exact)
Both units are defined exactly, so the factor is exact. Joule definition: joule; Calorie definition: calorie.
Worked examples
- 4184 J is 1000 cal, one food Calorie.
4184 J × 0.2390057361 = 1000 cal - 100 J is 23.90057361 cal.
100 J × 0.2390057361 = 23.90057361 cal
Joule to Calorie conversion table
| Joules (J) | Calories (cal) |
|---|---|
| 1 J | 0.2390057361 cal |
| 10 J | 2.390057361 cal |
| 100 J | 23.90057361 cal |
| 250 J | 59.75143403 cal |
| 500 J | 119.5028681 cal |
| 1000 J | 239.0057361 cal |
| 4184 J | 1000 cal |
| 10000 J | 2390.057361 cal |
| 100000 J | 23900.57361 cal |
| 1000000 J | 239005.7361 cal |
| 3600000 J | 860420.6501 cal |
Where it's used
Joule results are converted to calories for comparison with older chemistry tables and nutrition contexts.
Joule to other energy units
| Conversion | 1 J equals |
|---|---|
| joule to kilojoule | 0.001 kJ |
| joule to megajoule | 0.000001 MJ |
| joule to calorie | 0.2390057361 cal |
| joule to kilocalorie | 0.0002390057361 kcal |
| joule to watt-hour | 0.0002777777778 Wh |
| joule to kilowatt-hour | 2.777777778 × 10⁻⁷ kWh |
| joule to BTU | 0.0009478171203 BTU |
| joule to therm | 9.48043428 × 10⁻⁹ thm |
| joule to electronvolt | 6.241509074 × 10¹⁸ eV |
| joule to foot-pound | 0.7375621493 ft·lbf |
| joule to erg | 10000000 erg |
Frequently asked questions
How many calories are in a joule?
1 J = 0.239006 cal (thermochemical).
How many calories are in 1 joule?
1 J = 0.2390057361 cal.
How do I convert joules to calories?
Multiply the value in J by 0.2390057361, or divide it by 4.184. For example, 15 J × 0.2390057361 = 3.585086042 cal.
Is the J 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 4, coherent derived units with special names.
- 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 Joules to Calories. Retrieved October 17, 2026, from https://scientificconverters.com/energy/joules-to-calories/
IEEE
Scientific Converters, "Convert Joules to Calories," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/joules-to-calories/