Convert Kilocalories to Joules
1 kilocalorie (kcal) equals 4184 joules (J).
1 kcal = 4184 J
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk kilocalorie to joule converter to paste a column from Excel.
How to Convert Kilocalorie to Joule
- 1 kcal = 4184 J
- 1 J = 0.0002390057361 kcal
- Example: convert 15 kcal to J: 15 kcal = 15 × 4184 J = 62760 J
Reference conditions. kcal: Thermochemical kilocalorie (food Calorie), 4184 J exactly.
Formula
J = kcal × 4184
Derivation from SI units:
- 1 kcal = 1000 cal = 4184 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. Kilocalorie definition: kilocalorie; Joule definition: joule.
Worked examples
- A reading of 200 kcal converts to 836800 J.
200 kcal × 4184 = 836800 J - A value of 1500 kcal is 6276000 J.
1500 kcal × 4184 = 6276000 J
Kilocalorie to Joule conversion table
| Kilocalories (kcal) | Joules (J) |
|---|---|
| 1 kcal | 4184 J |
| 50 kcal | 209200 J |
| 100 kcal | 418400 J |
| 150 kcal | 627600 J |
| 200 kcal | 836800 J |
| 250 kcal | 1046000 J |
| 300 kcal | 1255200 J |
| 500 kcal | 2092000 J |
| 1000 kcal | 4184000 J |
| 1500 kcal | 6276000 J |
| 2000 kcal | 8368000 J |
| 2500 kcal | 10460000 J |
| 3000 kcal | 12552000 J |
| 3500 kcal | 14644000 J |
Where it's used
Kilocalories are used for food and diet energy (2000 kcal reference intake), while joules appear in physics and engineering energy balances. Both measure energy, work and heat, so the conversion is a fixed factor.
Kilocalorie to other energy units
| Conversion | 1 kcal equals |
|---|---|
| kilocalorie to joule | 4184 J |
| kilocalorie to kilojoule | 4.184 kJ |
| kilocalorie to megajoule | 0.004184 MJ |
| kilocalorie to calorie | 1000 cal |
| kilocalorie to watt-hour | 1.162222222 Wh |
| kilocalorie to kilowatt-hour | 0.001162222222 kWh |
| kilocalorie to BTU | 3.965666831 BTU |
| kilocalorie to therm | 0.00003966613703 thm |
| kilocalorie to electronvolt | 2.611447397 × 10²² eV |
| kilocalorie to foot-pound | 3085.960033 ft·lbf |
| kilocalorie to erg | 41840000000 erg |
Frequently asked questions
How many joules are in 1 kilocalorie?
1 kcal = 4184 J.
How do I convert kilocalories to joules?
Multiply the value in kcal by 4184. For example, 15 kcal × 4184 = 62760 J.
Is the kcal to J conversion exact?
Yes. Both units are defined exactly, and 1 kcal is exactly 4184 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, "kilocalorie (thermochemical)".
- 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 Kilocalories to Joules. Retrieved October 17, 2026, from https://scientificconverters.com/energy/kilocalories-to-joules/
IEEE
Scientific Converters, "Convert Kilocalories to Joules," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/kilocalories-to-joules/