How many joules are in 1 electronvolt?

1 electronvolt equals 1.60218e-19 J.

How do I convert joules back to electronvolts?

Use the reverse converter: 1 joule equals 6.24151e+18 eV.

Yes. It uses the exact SI/NIST definitions of each unit and shows up to 6 significant digits.

To convert electronvolts to joules, multiply the value by 1.60217663e-19.

J = eV × 1.60217663e-19

40 eV × 1.60217663e-19 = 6.40871e-18 J

Electronvolt (eV): Used in particle and atomic physics. Exactly 1.602176634×10⁻¹⁹ joules.
Joule (J): The SI unit of energy, one newton-metre, named after James Prescott Joule.

How do I convert electronvolts to joules?: To convert electronvolts to joules, multiply the value by 1.60217663e-19.
How many joules are in 1 electronvolt?: 1 electronvolt equals 1.60218e-19 J.
How many joules are in 10 electronvolts?: 10 eV equals 1.60218e-18 J.
How do I convert joules back to electronvolts?: Use the reverse converter: 1 joule equals 6.24151e+18 eV.
Is this converter accurate?: Yes. It uses the exact SI/NIST definitions of each unit and shows up to 6 significant digits.