eV to Volts Calculator

Convert electron volts to volts instantly. Calculate voltage from energy and charge for atomic physics, quantum mechanics, and semiconductor applications.

Electron
-1.602×10⁻¹⁹ C
Proton
+1.602×10⁻¹⁹ C
Alpha Particle
+3.204×10⁻¹⁹ C
Enter the energy in selected units
Enter the electric charge in selected units
1 eV / e
Hydrogen Ionization
Electron Rest Energy
1 keV / e
1 MeV / 2e
1 eV in SI units
5 eV / Proton
10 keV / α-particle
Conversion Result
1 eV / e = 1 V
Energy
1 eV
Electron Volts eV
Charge
1 e
Elementary Charge e
Voltage
1 V
Volts V
Equivalent Voltage for Different Particles
1.00
Electron (1e)
1.00
Proton (+e)
0.50
Alpha (+2e)
0.10
+10e Ion

Voltage Formula: V (Volts) = E (Joules) / Q (Coulombs)

Calculation: (1 eV × 1.602×10⁻¹⁹ J/eV) / (1 e × 1.602×10⁻¹⁹ C/e) = 1 V

Understanding Electron Volts (eV) and Volts (V)

An electron volt (eV) is a unit of energy equal to the amount of kinetic energy gained by a single electron when it accelerates through an electric potential difference of one volt. A volt (V) is a unit of electrical potential difference. The relationship between energy in eV and voltage depends on the charge of the particle.

Fundamental Relationship:

Energy (in joules) = Voltage (in volts) × Charge (in coulombs)

E (J) = V (V) × Q (C)

Since 1 eV = 1.602176634×10⁻¹⁹ J and e = 1.602176634×10⁻¹⁹ C:

For a particle with charge e: V (V) = E (eV) × (1.602×10⁻¹⁹ J/eV) / (1.602×10⁻¹⁹ C/e) = E (eV)

Energy Unit Conversions

Energy Unit Electron Volt Equivalent Joule Equivalent Common Usage
Electron Volt (eV) eV 1 eV 1.602×10⁻¹⁹ J Atomic and molecular physics
Millielectron Volt (meV) 0.001 eV 1.602×10⁻²² J Thermal energy at low temperatures
Kiloelectron Volt (keV) 1,000 eV 1.602×10⁻¹⁶ J X-ray energies, electron microscopy
Megaelectron Volt (MeV) 1,000,000 eV 1.602×10⁻¹³ J Nuclear physics, radiation therapy
Gigaelectron Volt (GeV) 1,000,000,000 eV 1.602×10⁻¹⁰ J Particle physics, cosmic rays
Joule (J) 6.242×10¹⁸ eV 1 J SI unit of energy

Charge Unit Conversions

Charge Unit Coulomb Equivalent Elementary Charge Equivalent Common Usage
Elementary Charge (e) e 1.602×10⁻¹⁹ C 1 e Electron or proton charge
Coulomb (C) 1 C 6.242×10¹⁸ e SI unit of charge
Millicoulomb (mC) 0.001 C 6.242×10¹⁵ e Small charge measurements
Proton Charge (+e) 1.602×10⁻¹⁹ C 1 e Proton, positron
Alpha Particle Charge (+2e) 3.204×10⁻¹⁹ C 2 e Helium nucleus

Practical Applications

1

Atomic Physics: The ionization energy of hydrogen is 13.6 eV. For an electron (charge e), this corresponds to accelerating through 13.6 volts. In a hydrogen atom, the electron needs 13.6 eV of energy to escape the proton's attraction.

2

Semiconductor Physics: In semiconductor devices, the band gap energy is measured in eV. For silicon, the band gap is 1.12 eV at room temperature. This determines the voltage required to excite electrons from the valence band to the conduction band.

3

Particle Accelerators: Particle accelerators use electric fields to give particles energy measured in MeV or GeV. For example, an electron with 1 MeV of energy has been accelerated through approximately 1 million volts (if it has charge e).

Common eV to Volt Conversions

Energy (eV) Particle / Charge Voltage (V) Application / Example
1 eV Electron (e) 1 V Definition of electron volt
13.6 eV Electron (e) 13.6 V Hydrogen ionization energy
2.1 eV Electron (e) 2.1 V Red light photon energy
511 keV Electron (e) 511,000 V Electron rest mass energy
1 MeV Proton (+e) 1,000,000 V Medical proton therapy
5 MeV Alpha particle (+2e) 2,500,000 V Alpha decay energy
7 TeV Proton (+e) 7×10¹² V LHC proton energy (per beam)
1.12 eV Electron (e) 1.12 V Silicon band gap

Calculator Features:

  • Convert energy in eV (and multiples) to voltage
  • Support for various charge units including elementary charge
  • Includes common particles: electron, proton, alpha particle
  • Shows equivalent voltage for different particles with same energy
  • Mobile-friendly interface with responsive design

Frequently Asked Questions

By definition, 1 electron volt (1 eV) is the kinetic energy gained by an electron when it accelerates through an electric potential difference of 1 volt. Since an electron has charge e = 1.602×10⁻¹⁹ C, and energy = charge × voltage, we have: 1 eV = e × 1 V. So for an electron, the numerical value of energy in eV equals the numerical value of voltage in volts.

Voltage is energy per unit charge (V = E/Q). For the same energy, a particle with larger charge requires less voltage to achieve that energy. For example, an alpha particle has charge +2e, so it needs only half the voltage to achieve the same energy as an electron. With 1 MeV of energy: an electron (charge e) needs 1 MV, while an alpha particle (charge 2e) needs only 0.5 MV.

1 electron volt equals 1.602176634×10⁻¹⁹ joules. This conversion factor comes from the elementary charge (e). Since 1 eV = e × 1 V and e = 1.602176634×10⁻¹⁹ C, and 1 J = 1 C × 1 V, we get the conversion. The 2019 redefinition of SI units fixed the value of e exactly, making 1 eV exactly 1.602176634×10⁻¹⁹ J.

Electron volts are more convenient for atomic-scale energies because the numbers are much more manageable. Typical atomic energies are on the order of eV (e.g., hydrogen ionization is 13.6 eV), while in joules this would be about 2.18×10⁻¹⁸ J - a very small number. Using eV also directly relates to the voltages used in experiments: a 13.6 V potential gives electrons 13.6 eV of energy.

For photons or neutral particles, the concept of voltage doesn't directly apply because voltage is defined for charged particles. Photons have energy but no charge, so they can't be accelerated by electric fields. However, you can use the calculator to find what voltage would give a charged particle the same energy as a photon. For example, a 2 eV photon has the same energy as an electron that has been accelerated through 2 volts.