How many watt-hours are in one electronvolt?

1 eV = approximately 4.4505×10⁻²³ Wh. This is derived from 1 eV = 1.602176634×10⁻¹⁹ J and 1 Wh = 3,600 J, so 1 eV = 1.602176634×10⁻¹⁹ / 3,600 ≈ 4.4505×10⁻²³ Wh.

Why is the watt-hour value so small for eV inputs?

The electronvolt is an atomic-scale unit — extraordinarily small compared to watt-hours used on electricity bills. Even 1 MeV (10⁶ eV) equals only about 4.45×10⁻¹⁷ Wh, far below anything measurable in everyday energy contexts.

What is the difference between eV, keV, MeV, and GeV?

1 keV = 1,000 eV; 1 MeV = 10⁶ eV; 1 GeV = 10⁹ eV. Atomic electrons are bound by a few eV, X-rays carry keV energies, nuclear reactions involve MeV, and particle accelerators operate at GeV and higher.

Can I convert watt-hours back to electronvolts?

Yes — switch to Wh/kWh → eV mode in this tool. The reverse conversion: 1 Wh = 3,600 J / 1.602176634×10⁻¹⁹ J per eV ≈ 2.247×10²² eV.

How do I enter scientific notation?

Use standard e-notation: for 1.5×10⁶ type "1.5e6". For 2.5×10⁻³ type "2.5e-3". The tool accepts this format directly in the input field.

Electronvolts to Watt Hours Converter

Enter energy in eV, keV, MeV, or GeV and get watt-hours and kilowatt-hours instantly. 1 eV = 4.4505×10⁻²³ Wh.

Energy Converter

eV Unit

Energy in Electronvolts (eV)

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kWh

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1 eV = 4.4505×10⁻²³ Wh | 1 Wh ≈ 2.247×10²² eV

eV ↔ Wh Reference Table

Common energy values in electronvolts and their watt-hour equivalents

Electronvolts	Wh	Context

1 eV = 1.602176634×10⁻¹&sup9; J • 1 Wh = 3,600 J • 1 eV ≈ 4.4505×10⁻²³ Wh

Summary

This converter transforms electronvolts (eV) — and the multiples keV, MeV, GeV — into watt-hours (Wh) or kilowatt-hours (kWh). The conversion chain is: 1 eV = 1.602176634×10⁻¹⁹ J, and 1 Wh = 3,600 J, giving 1 eV = 1.602176634×10⁻¹⁹ / 3,600 ≈ 4.4505×10⁻²³ Wh. Watt-hours are used in energy storage, batteries, and electricity billing, while electronvolts are the standard unit in atomic and particle physics. The tool is bidirectional: enter Wh or kWh to convert back to eV.

How it works

Select the input unit: eV, keV, MeV, or GeV from the dropdown.
Enter any numeric value — whole numbers, decimals, or scientific notation (e.g. 1.5e6).
Results appear instantly in watt-hours (Wh) and kilowatt-hours (kWh).
Switch to Wh/kWh → eV mode to reverse the conversion.
Click any result to copy the value to your clipboard.

Use cases

Convert particle beam energy from MeV to watt-hours for power budget comparisons.
Translate photon energies in eV to Wh for solar cell efficiency calculations.
Cross-reference nuclear reaction Q-values in MeV with practical energy units.
Convert ionization energies in eV to watt-hours for battery chemistry research.
Check how many electronvolts of energy a given watt-hour capacity represents.
Bridge atomic-scale energy units with grid-scale watt-hour measurements.

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu