Convert Joules to Electronvolts
1 joule (J) equals 6.241509074 × 10¹⁸ electronvolts (eV).
1 J = 6.241509074e18 eV
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk joule to electronvolt converter to paste a column from Excel.
How to Convert Joule to Electronvolt
- 1 J = 6.241509074 × 10¹⁸ eV
- 1 eV = 1.602176634 × 10⁻¹⁹ J
- Example: convert 15 J to eV: 15 J = 15 × 6.241509074 × 10¹⁸ eV = 9.362263612 × 10¹⁹ eV
Formula
eV = J × 6.241509074461 × 10¹⁸
Derivation from SI units:
- 1 J = 1 N·m = 1 W·s = 1 kg·m²·s⁻²
- 1 eV = e × 1 V = 1.602176634 × 10⁻¹⁹ J (exact since 2019)
Both units are defined exactly, so the factor is exact. Joule definition: joule; Electronvolt definition: electronvolt.
Worked examples
- 1 J is 6.241509074 × 10¹⁸ eV.
1 J × 6.241509074 × 10¹⁸ = 6.241509074 × 10¹⁸ eV - A visible-light photon of about 3.0e-19 J carries 1.872452722 eV.
3.0e-19 J × 6.241509074 × 10¹⁸ = 1.872452722 eV
Joule to Electronvolt conversion table
| Joules (J) | Electronvolts (eV) |
|---|---|
| 1 J | 6.241509074 × 10¹⁸ eV |
| 10 J | 6.241509074 × 10¹⁹ eV |
| 100 J | 6.241509074 × 10²⁰ eV |
| 250 J | 1.560377269 × 10²¹ eV |
| 500 J | 3.120754537 × 10²¹ eV |
| 1000 J | 6.241509074 × 10²¹ eV |
| 4184 J | 2.611447397 × 10²² eV |
| 10000 J | 6.241509074 × 10²² eV |
| 100000 J | 6.241509074 × 10²³ eV |
| 1000000 J | 6.241509074 × 10²⁴ eV |
| 3600000 J | 2.246943267 × 10²⁵ eV |
Where it's used
Small SI energies are converted to electronvolts to compare with photon, band-gap and ionisation energies.
Joule to other energy units
| Conversion | 1 J equals |
|---|---|
| joule to kilojoule | 0.001 kJ |
| joule to megajoule | 0.000001 MJ |
| joule to calorie | 0.2390057361 cal |
| joule to kilocalorie | 0.0002390057361 kcal |
| joule to watt-hour | 0.0002777777778 Wh |
| joule to kilowatt-hour | 2.777777778 × 10⁻⁷ kWh |
| joule to BTU | 0.0009478171203 BTU |
| joule to therm | 9.48043428 × 10⁻⁹ thm |
| joule to electronvolt | 6.241509074 × 10¹⁸ eV |
| joule to foot-pound | 0.7375621493 ft·lbf |
| joule to erg | 10000000 erg |
Frequently asked questions
How many eV is 1 joule?
1 J = 6.241509074 × 10¹⁸ eV.
How many electronvolts are in 1 joule?
1 J = 6.241509074 × 10¹⁸ eV.
How do I convert joules to electronvolts?
Multiply the value in J by 6.241509074 × 10¹⁸. For example, 15 J × 6.241509074 × 10¹⁸ = 9.362263612 × 10¹⁹ eV.
Is the J to eV conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 8 and the fixed elementary charge e.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Joules to Electronvolts. Retrieved October 17, 2026, from https://scientificconverters.com/energy/joules-to-electronvolts/
IEEE
Scientific Converters, "Convert Joules to Electronvolts," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/joules-to-electronvolts/