Convert Calories to Electronvolts
1 calorie (cal) equals 2.611447397 × 10¹⁹ electronvolts (eV).
1 cal = 2.611447397e19 eV
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk calorie to electronvolt converter to paste a column from Excel.
How to Convert Calorie to Electronvolt
- 1 cal = 2.611447397 × 10¹⁹ eV
- 1 eV = 3.829294058 × 10⁻²⁰ cal
- Example: convert 15 cal to eV: 15 cal = 15 × 2.611447397 × 10¹⁹ eV = 3.917171095 × 10²⁰ eV
Reference conditions. cal: Thermochemical calorie, 4.184 J exactly. The International Table calorie is 4.1868 J.
Formula
eV = cal × 2.611447396754 × 10¹⁹
Derivation from SI units:
- 1 cal (thermochemical) = 4.184 J (exact)
- 1 eV = e × 1 V = 1.602176634 × 10⁻¹⁹ J (exact since 2019)
- 1 cal = 4.184 J ÷ 1.602176634 × 10⁻¹⁹ J per eV = 2.611447396754 × 10¹⁹ eV
Both units are defined exactly, so the factor is exact. Calorie definition: calorie; Electronvolt definition: electronvolt.
Worked examples
- A reading of 100 cal converts to 2.611447397 × 10²¹ eV.
100 cal × 2.611447397 × 10¹⁹ = 2.611447397 × 10²¹ eV - A value of 1000 cal is 2.611447397 × 10²² eV.
1000 cal × 2.611447397 × 10¹⁹ = 2.611447397 × 10²² eV
Calorie to Electronvolt conversion table
| Calories (cal) | Electronvolts (eV) |
|---|---|
| 1 cal | 2.611447397 × 10¹⁹ eV |
| 10 cal | 2.611447397 × 10²⁰ eV |
| 100 cal | 2.611447397 × 10²¹ eV |
| 250 cal | 6.528618492 × 10²¹ eV |
| 500 cal | 1.305723698 × 10²² eV |
| 1000 cal | 2.611447397 × 10²² eV |
| 4184 cal | 1.092629591 × 10²³ eV |
| 10000 cal | 2.611447397 × 10²³ eV |
Where it's used
Calories are used for chemistry and calorimetry, while electronvolts appear in atomic and particle physics. Both measure energy, work and heat, so the conversion is a fixed factor.
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
How many electronvolts are in 1 calorie?
1 cal = 2.611447397 × 10¹⁹ eV.
How do I convert calories to electronvolts?
Multiply the value in cal by 2.611447397 × 10¹⁹. For example, 15 cal × 2.611447397 × 10¹⁹ = 3.917171095 × 10²⁰ eV.
Is the cal to eV 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
- 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 8 and the fixed elementary charge e.
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 Electronvolts. Retrieved October 17, 2026, from https://scientificconverters.com/energy/calories-to-electronvolts/
IEEE
Scientific Converters, "Convert Calories to Electronvolts," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/calories-to-electronvolts/