Electronvolt (eV)
A unit of energy used in atomic and particle physics
The Electronvolt (eV) is a unit of energy that emerged from one of several distinct scientific and practical traditions. The study of energy unified previously separate fields — mechanics, heat, electricity — under a common framework in the 19th century. James Joule's famous paddle-wheel experiments helped establish the equivalence of mechanical work and heat, leading to the joule as the SI unit. The Electronvolt reflects the conventions of its origin discipline, whether thermal engineering, nutrition, electrical power, or mechanics.
Accurate energy measurement is critical in engineering, science, commerce, and everyday life. Using the correct unit and applying conversions precisely prevents errors that can be costly or dangerous in professional applications.
Conversion Table
| Unit | Symbol | 1 eV = |
|---|---|---|
| Joule | J | 1.602177e-19 J |
| Kilojoule | kJ | 1.602177e-22 kJ |
| Calorie | cal | 3.829294e-20 cal |
| Kilocalorie | kcal | 3.829294e-23 kcal |
| Kilowatt Hour | kWh | 4.450491e-26 kWh |
| British Thermal Unit | BTU | 1.518564e-22 BTU |
Conversions Involving Electronvolt
Joule → Electronvolt
J → eV
Kilojoule → Electronvolt
kJ → eV
Calorie → Electronvolt
cal → eV
Kilocalorie → Electronvolt
kcal → eV
Kilowatt Hour → Electronvolt
kWh → eV
British Thermal Unit → Electronvolt
BTU → eV
Electronvolt → Joule
eV → J
Electronvolt → Kilojoule
eV → kJ
Electronvolt → Calorie
eV → cal
Electronvolt → Kilocalorie
eV → kcal
Electronvolt → Kilowatt Hour
eV → kWh
Electronvolt → British Thermal Unit
eV → BTU
Common Uses of the Electronvolt
- •Electricity billing — measuring household and industrial energy consumption
- •Nutrition — expressing the energy content of food on product labels
- •Mechanical engineering — calculating work done by forces and machines
- •Chemical engineering — accounting for heat of reaction in process design
- •Renewable energy — measuring solar panel and battery system output
Did You Know?
A single lightning bolt releases approximately 1–5 gigajoules (GJ) of energy in about 0.2 seconds — enough to power a 100-watt light bulb for about 3 months if it could be captured. The Electronvolt provides a scale for understanding energy across the enormous range from subatomic particle interactions to stellar phenomena.