Electronvolts ↔ Joules Converter

Convert between electronvolts (eV) and joules (J) instantly

Enter eV value to convert to joules
Enter joules value to convert to eV
Conversion Result
1 eV = 1.602×10⁻¹⁹ J
1.602176634 × 10⁻¹⁹ joules
🔄 Conversions happen automatically as you type in either field

📚 Electronvolts ↔ Joules Conversion Details

Electronvolts to Joules Formula

1 eV = 1.602176634 × 10⁻¹⁹ J

To convert electronvolts to joules, multiply the eV value by 1.602176634×10⁻¹⁹.

Joules to Electronvolts Formula

1 J = 6.241509074 × 10¹⁸ eV

To convert joules to electronvolts, multiply the joules value by 6.241509074×10¹⁸.

Bidirectional Conversion

This converter works both ways simultaneously:

  • Type in eV → joules updates automatically
  • Type in joules → eV updates automatically
  • No buttons to click - works as you type

Common Uses

  • Particle physics
  • Atomic physics
  • Quantum mechanics
  • Energy level calculations

📏 What are Electronvolts?

The electronvolt (symbol: eV) is a unit of energy equal to approximately 1.602×10⁻¹⁹ joules. It is defined as the amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacuum.

// Conversion Factors (Exact 2019 redefinition):
1 eV = 1.602176634 × 10⁻¹⁹ J (exact)
1 J = 6.241509074 × 10¹⁸ eV

// Example 1: 5 eV to joules
5 × 1.602176634e-19 = 8.01088317e-19 J

// Example 2: 1.5×10⁻¹⁸ J to eV
1.5e-18 × 6.241509074e18 = 9.362263611 eV

📊 Common eV to J Conversions

Electronvolts Joules Scientific Notation
1 eV 1.602176634×10⁻¹⁹ J 1.602176634e-19
1 keV (1000 eV) 1.602176634×10⁻¹⁶ J 1.602176634e-16
1 MeV (10⁶ eV) 1.602176634×10⁻¹³ J 1.602176634e-13
1 GeV (10⁹ eV) 1.602176634×10⁻¹⁰ J 1.602176634e-10
1 TeV (10¹² eV) 1.602176634×10⁻⁷ J 1.602176634e-7
1 J 6.241509074×10¹⁸ eV 6.241509074e18

🎯 Energy Scale Reference

Typical Energy Ranges:

  • Chemical bond energies: 1-10 eV
  • Visible photon energies: 1.6-3.1 eV
  • Medical X-rays: 10-100 keV
  • Nuclear gamma rays: 0.1-10 MeV
  • Cosmic rays: 1 GeV - 1 TeV+
  • LHC proton collisions: 6.5 TeV per beam

❓ Frequently Asked Questions

Q: Why use electronvolts instead of joules?

A: Electronvolts are convenient for atomic-scale energies where joules would involve very small decimal numbers (10⁻¹⁹ scale). 1 eV is the energy gained by an electron moving through 1 volt.

Q: Is the conversion factor exact?

A: Yes! Since the 2019 SI redefinition, 1 eV = 1.602176634×10⁻¹⁹ J exactly (no uncertainty).

Q: How does bidirectional conversion work?

A: Both input fields work simultaneously. When you change the eV value, joules updates automatically. When you change joules, eV updates automatically.

Q: What are common prefixes for eV?

A: keV (kilo-electronvolts, 10³ eV), MeV (mega-electronvolts, 10⁶ eV), GeV (giga-electronvolts, 10⁹ eV), TeV (tera-electronvolts, 10¹² eV).