Convert Electronvolts to Kilocalories
Instantly convert Electronvolts (eV) to Kilocalories (kcal) with our free online calculator.
Formula: eV to kcal — multiply by 3.8293e-23
Reference Table
| Electronvolts (eV) | Kilocalories (kcal) |
|---|---|
| 1 | 3.829294e-23 |
| 5 | 1.914647e-22 |
| 10 | 3.829294e-22 |
| 25 | 9.573235e-22 |
| 50 | 1.914647e-21 |
| 100 | 3.829294e-21 |
How to Convert Electronvolts to Kilocalories
Formula
To convert Electronvolts (eV) to Kilocalories (kcal): multiply by 3.8293e-23
Step-by-Step
- Start with your value in Electronvolts (eV).
- Multiply by 3.8293e-23 to perform the conversion.
- The result is your value expressed in Kilocalories (kcal).
Conversion Factor
1 eV = 3.829294e-23 kcal
Reverse Factor
1 kcal = 2.611447e+22 eV
Worked Example
Convert 25 Electronvolts to Kilocalories: 25 eV = 9.573235e-22 kcal
About Electronvolt (eV)
A unit of energy equal to the kinetic energy gained by an electron accelerating through an electric potential difference of one volt in vacuum, defined since the 2019 SI redefinition as exactly 1.602176634 × 10⁻¹⁹ joules (CODATA 2018, BIPM SI Brochure). The electronvolt is the natural working unit of atomic, molecular, and particle physics where joules are too large to be convenient: chemical bond energies are a few eV (C-C bond ~3.6 eV, O-H bond ~4.8 eV), photon energies in the visible spectrum are 1.6-3.1 eV (red to violet), X-rays carry keV (medical diagnostic ~80-140 keV, hard X-ray ~10-100 keV), nuclear-reaction Q-values are MeV (fission of U-235 releases ~200 MeV per atom), particle-collider beam energies are GeV-TeV (LHC operates at 13.6 TeV center-of-mass), and astrophysical sources reach PeV / EeV (highest-energy cosmic rays ~3 × 10²⁰ eV = 300 EeV). Particle physics papers in Physical Review D, JHEP, Nature Physics, and the PDG Review of Particle Physics report all energies, masses (E = mc² gives a free conversion), and cross-sections in eV or its derivatives. 1 eV ≈ 1.602 × 10⁻¹⁹ J ≈ 1.602 × 10⁻¹² erg.
About Kilocalorie (kcal)
A unit of energy equal to exactly 1,000 gram-calories (= exactly 4,184 joules per the thermochemical definition). This is the unit behind the 'Calorie' (capital C) on US food packaging — a 200-Calorie granola bar contains 200 kcal = 200,000 small calories = 836 kJ. Adult daily dietary intake per FDA / USDA Dietary Guidelines is 1,600-2,400 kcal for women and 2,000-3,000 kcal for men depending on age and activity, with WHO baseline targets of 2,000 / 2,500 kcal. Indirect calorimetry (gold-standard metabolic rate measurement) reports BMR / TDEE in kcal/day. Kilocalories are also used for refrigeration / heating-system output in some legacy European industrial specifications (kcal/h sometimes appears on older boilers and chillers, though kW has largely replaced it), and for muscle-physiology energy-expenditure reporting in exercise science. The 'Atwater system' (4-9-4 macronutrient values: 4 kcal/g protein, 9 kcal/g fat, 4 kcal/g carbohydrate) is the calculation method behind almost every nutrition label.
Quick Facts
- 1 Electronvolt equals 3.829294e-23 Kilocalories
- 1 Kilocalorie equals 2.611447e+22 Electronvolts
- Electronvolt is a unit of energy
- Kilocalorie is a unit of energy
- This conversion is commonly used in nutrition, electrical billing, physics, and mechanical engineering
Common Electronvolt to Kilocalorie Conversions
| Electronvolts (eV) | Kilocalories (kcal) |
|---|---|
| 0.01 | 3.829294e-25 |
| 0.1 | 3.829294e-24 |
| 0.25 | 9.573235e-24 |
| 0.5 | 1.914647e-23 |
| 1 | 3.829294e-23 |
| 2 | 7.658588e-23 |
| 3 | 1.148788e-22 |
| 5 | 1.914647e-22 |
| 10 | 3.829294e-22 |
| 15 | 5.743941e-22 |
| 20 | 7.658588e-22 |
| 25 | 9.573235e-22 |
| 50 | 1.914647e-21 |
| 75 | 2.871971e-21 |
| 100 | 3.829294e-21 |
| 250 | 9.573235e-21 |
| 500 | 1.914647e-20 |
| 1000 | 3.829294e-20 |
| 5000 | 1.914647e-19 |
| 10000 | 3.829294e-19 |
Understanding Electronvolts
The Electronvolt (symbol: eV) is a unit of energy. A unit of energy equal to the kinetic energy gained by an electron accelerating through an electric potential difference of one volt in vacuum, defined since the 2019 SI redefinition as exactly 1.602176634 × 10⁻¹⁹ joules (CODATA 2018, BIPM SI Brochure). The electronvolt is the natural working unit of atomic, molecular, and particle physics where joules are too large to be convenient: chemical bond energies are a few eV (C-C bond ~3.6 eV, O-H bond ~4.8 eV), photon energies in the visible spectrum are 1.6-3.1 eV (red to violet), X-rays carry keV (medical diagnostic ~80-140 keV, hard X-ray ~10-100 keV), nuclear-reaction Q-values are MeV (fission of U-235 releases ~200 MeV per atom), particle-collider beam energies are GeV-TeV (LHC operates at 13.6 TeV center-of-mass), and astrophysical sources reach PeV / EeV (highest-energy cosmic rays ~3 × 10²⁰ eV = 300 EeV). Particle physics papers in Physical Review D, JHEP, Nature Physics, and the PDG Review of Particle Physics report all energies, masses (E = mc² gives a free conversion), and cross-sections in eV or its derivatives. 1 eV ≈ 1.602 × 10⁻¹⁹ J ≈ 1.602 × 10⁻¹² erg.
Electronvolts are commonly used in nutrition, electrical billing, physics, and mechanical engineering.
Understanding Kilocalories
The Kilocalorie (symbol: kcal) is a unit of energy. A unit of energy equal to exactly 1,000 gram-calories (= exactly 4,184 joules per the thermochemical definition). This is the unit behind the 'Calorie' (capital C) on US food packaging — a 200-Calorie granola bar contains 200 kcal = 200,000 small calories = 836 kJ. Adult daily dietary intake per FDA / USDA Dietary Guidelines is 1,600-2,400 kcal for women and 2,000-3,000 kcal for men depending on age and activity, with WHO baseline targets of 2,000 / 2,500 kcal. Indirect calorimetry (gold-standard metabolic rate measurement) reports BMR / TDEE in kcal/day. Kilocalories are also used for refrigeration / heating-system output in some legacy European industrial specifications (kcal/h sometimes appears on older boilers and chillers, though kW has largely replaced it), and for muscle-physiology energy-expenditure reporting in exercise science. The 'Atwater system' (4-9-4 macronutrient values: 4 kcal/g protein, 9 kcal/g fat, 4 kcal/g carbohydrate) is the calculation method behind almost every nutrition label.
Kilocalories are commonly used in nutrition, electrical billing, physics, and mechanical engineering.
Why Convert Electronvolts to Kilocalories?
Converting energy between Electronvolts and Kilocalories is common in physics, nutrition, and engineering. Electricity bills use kilowatt-hours, food labels list calories or kilojoules, and mechanical engineers work with joules and BTUs. Reliable conversion helps professionals and consumers compare energy values across different contexts.
Frequently Asked Questions
How do I convert Electronvolts to Kilocalories?
A unit of energy equal to the kinetic energy gained by an electron accelerating through an electric potential difference of one volt in vacuum, defined since the 2019 SI redefinition as exactly 1. To convert Electronvolts to Kilocalories, multiply by 3.8293e-23. For example, 25 eV equals 9.573235e-22 kcal.
How many Kilocalories are in 1 Electronvolt?
There are 3.829294e-23 Kilocalories in 1 Electronvolt.
How many Electronvolts are in 1 Kilocalorie?
There are 2.611447e+22 Electronvolts in 1 Kilocalorie.
What is the formula for Electronvolt to Kilocalorie conversion?
The formula is: multiply by 3.8293e-23. This means 1 eV = 3.829294e-23 kcal.
Is a Electronvolt bigger than a Kilocalorie?
Yes. One Electronvolt is larger than one Kilocalorie because 1 eV equals 3.829294e-23 kcal, which is less than 1.
When do you need to convert between Electronvolts and Kilocalories?
A unit of energy equal to exactly 1,000 gram-calories (= exactly 4,184 joules per the thermochemical definition). Electronvolt and Kilocalorie are both energy units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.