Electronvolts to joules (eV to J)

1 eV = 1.602176634 × 10⁻¹⁹ J exactly. To convert electronvolts to joules, multiply by 1.602176634 × 10⁻¹⁹.

The formula

J = eV × 1.602176634 × 10⁻¹⁹

Where the factor comes from — each unit by its definition, then its size in SI:

  • 1 eV = e (elementary charge in C, CODATA 2022) × J = 1.602176634 × 10⁻¹⁹ J
  • 1 J is the SI unit of energy.

Dividing the two SI sizes gives the factor: 1.602176634 × 10⁻¹⁹, exact — every step above is a definition, not a measurement. The reverse factor is 6.24150907446 × 10¹⁸.

The SI unit of energy is the joule. Food labels use kilocalories, electricity bills kilowatt-hours, heating specs BTU and particle physics electronvolts — the same quantity in five costumes.

Worked examples

  • A day's food (2000 kcal): 5.22289 × 10²⁵ eV = 8,368,000 J — 5.22289 × 10²⁵ × 1.602176634 × 10⁻¹⁹ = 8,368,000
  • A 1 kW heater run for one hour (1 kWh): 2.24694 × 10²⁵ eV = 3,600,000 J — 2.24694 × 10²⁵ × 1.602176634 × 10⁻¹⁹ = 3,600,000
  • Lifting 1 kg through 1 m at standard gravity: 6.12083 × 10¹⁹ eV = 9.80665 J — 6.12083 × 10¹⁹ × 1.602176634 × 10⁻¹⁹ = 9.80665
  • A visible-light photon: 2 eV = 3.20435 × 10⁻¹⁹ J — 2 × 1.602176634 × 10⁻¹⁹ = 3.20435 × 10⁻¹⁹

Frequently asked questions

How many joules is 1 eV?

1 eV = 1.602176634 × 10⁻¹⁹ J, exactly, from the unit definitions.

How do I convert joules back to electronvolts?

Divide by 1.602176634 × 10⁻¹⁹ — or multiply by 6.24150907446 × 10¹⁸: 1 J = 6.24150907446 × 10¹⁸ eV.

eV to J conversion table

Electronvolts (eV)Joules (J)
11.6021766 × 10⁻¹⁹
23.2043533 × 10⁻¹⁹
34.8065299 × 10⁻¹⁹
46.4087065 × 10⁻¹⁹
58.0108832 × 10⁻¹⁹
69.6130598 × 10⁻¹⁹
71.1215236 × 10⁻¹⁸
81.2817413 × 10⁻¹⁸
91.441959 × 10⁻¹⁸
101.6021766 × 10⁻¹⁸
152.403265 × 10⁻¹⁸
203.2043533 × 10⁻¹⁸
254.0054416 × 10⁻¹⁸
304.8065299 × 10⁻¹⁸
406.4087065 × 10⁻¹⁸
508.0108832 × 10⁻¹⁸
609.6130598 × 10⁻¹⁸
701.1215236 × 10⁻¹⁷
751.2016325 × 10⁻¹⁷
801.2817413 × 10⁻¹⁷
901.441959 × 10⁻¹⁷
1001.6021766 × 10⁻¹⁷
1502.403265 × 10⁻¹⁷
2003.2043533 × 10⁻¹⁷
2504.0054416 × 10⁻¹⁷
5008.0108832 × 10⁻¹⁷
1,0001.6021766 × 10⁻¹⁶

Definitions: NIST CODATA 2022 complete listing — data/codata-2022.json · BIPM, The International System of Units (SI Brochure), 9th edition (2019), Tables 2, 4 and 8 — https://www.bipm.org/en/publications/si-brochure. Machine value of the factor: 1.602176634e-19.