Convert Calories to Joules
1 calorie (cal) equals 4.184 joules (J).
1 cal = 4.184 J
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk calorie to joule converter to paste a column from Excel.
How to Convert Calorie to Joule
- 1 cal = 4.184 J
- 1 J = 0.2390057361 cal
- Example: convert 15 cal to J: 15 cal = 15 × 4.184 J = 62.76 J
Reference conditions. cal: Thermochemical calorie, 4.184 J exactly. The International Table calorie is 4.1868 J.
Formula
J = cal × 4.184
Derivation from SI units:
- 1 cal (thermochemical) = 4.184 J (exact)
- 1 J = 1 N·m = 1 W·s = 1 kg·m²·s⁻²
Both units are defined exactly, so the factor is exact. Calorie definition: calorie; Joule definition: joule.
Worked examples
- Warming 1 g of water by about 1 °C takes 1 cal, or 4.184 J.
1 cal × 4.184 = 4.184 J - 1000 cal is 4184 J.
1000 cal × 4.184 = 4184 J
Calorie to Joule conversion table
| Calories (cal) | Joules (J) |
|---|---|
| 1 cal | 4.184 J |
| 10 cal | 41.84 J |
| 100 cal | 418.4 J |
| 250 cal | 1046 J |
| 500 cal | 2092 J |
| 1000 cal | 4184 J |
| 4184 cal | 17505.856 J |
| 10000 cal | 41840 J |
Where it's used
Calorimetry and older chemistry data in calories are converted to joules, the SI unit. This page uses the thermochemical calorie, 4.184 J.
Calorie to other energy units
| Conversion | 1 cal equals |
|---|---|
| calorie to joule | 4.184 J |
| calorie to kilojoule | 0.004184 kJ |
| calorie to megajoule | 0.000004184 MJ |
| calorie to kilocalorie | 0.001 kcal |
| calorie to watt-hour | 0.001162222222 Wh |
| calorie to kilowatt-hour | 0.000001162222222 kWh |
| calorie to BTU | 0.003965666831 BTU |
| calorie to therm | 3.966613703 × 10⁻⁸ thm |
| calorie to electronvolt | 2.611447397 × 10¹⁹ eV |
| calorie to foot-pound | 3.085960033 ft·lbf |
| calorie to erg | 41840000 erg |
Frequently asked questions
Is a calorie 4.184 or 4.1868 joules?
Both exist: the thermochemical calorie is 4.184 J and the International Table calorie 4.1868 J. Food energy uses 4.184 J.
How many joules are in 1 calorie?
1 cal = 4.184 J.
How do I convert calories to joules?
Multiply the value in cal by 4.184. For example, 15 cal × 4.184 = 62.76 J.
Is the cal to J conversion exact?
Yes. Both units are defined exactly, and 1 cal is exactly 4.184 J.
Sources
- 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)".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
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 Calories to Joules. Retrieved October 17, 2026, from https://scientificconverters.com/energy/calories-to-joules/
IEEE
Scientific Converters, "Convert Calories to Joules," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/calories-to-joules/