How many electronvolts are in one kilocalorie?

One kilocalorie equals approximately 2.61144×10²² eV. This comes from 1 kcal = 4184 J and 1 J = 6.24150907×10¹⁸ eV (the reciprocal of the elementary charge, fixed exactly in 2019 SI).

Is the kilocalorie used here a food calorie or a chemistry calorie?

Both. The food "Calorie" (capital C) is defined as 1 kcal = 1000 thermochemical calories = 4184 J exactly. This tool uses that definition, so 1 dietary Calorie and 1 thermochemical kcal give the same result.

Why are the eV values so large for small kcal amounts?

The electronvolt is an extremely tiny unit (1 eV ≈ 1.6×10⁻¹⁹ J), so even a small kilocalorie — already a modest amount of energy — corresponds to roughly 2.6×10²² eV. Scientific notation is essential to express these results accurately.

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

1 keV = 1,000 eV; 1 MeV = 10⁶ eV; 1 GeV = 10⁹ eV. Atomic electron binding energies are a few eV, X-rays carry keV energies, nuclear reactions involve MeV, and particle accelerators reach GeV and beyond.

How do I enter scientific notation?

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

Kilocalories to Electronvolts Converter

Name: Kilocalories to Electronvolts Converter
Availability: InStock
Author: Nham Vu

Enter energy in kilocalories to get electronvolts (eV), keV, MeV, and GeV — or enter eV to convert back. Uses 1 kcal = 4184 J = 2.61144×10²² eV.

Energy Converter

Energy in Kilocalories (kcal)

Electronvolts (eV)

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Kiloelectronvolts (keV)

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Megaelectronvolts (MeV)

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Gigaelectronvolts (GeV)

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1 kcal = 4184 J = 2.61144×10²² eV

kcal ↔ eV Reference Table

Common kilocalorie values and their electronvolt equivalents

Kilocalories (kcal)	Electronvolts (eV)	Context

1 kcal = 4184 J (thermochemical, exact) | 1 eV = 1.602176634×10⁻¹⁹ J (exact, 2019 SI)

Summary

Enter energy in kilocalories to get electronvolts (eV), keV, MeV, and GeV — or enter eV to convert back. Uses 1 kcal = 4184 J = 2.61144×10²² eV.

How it works

Select the conversion direction: kcal → eV or eV → kcal.
Type any numeric value — whole numbers, decimals, or scientific notation (e.g. 2.5e-3).
Results in eV, keV, MeV, and GeV appear instantly (or joules and kilocalories in reverse).
Click any result field to copy its value to the clipboard.
The reference table below shows common kcal-to-eV conversions for quick lookup.

Use cases

Convert dietary calorie counts (kcal) to electronvolt equivalents for physics coursework.
Bridge thermochemical reaction enthalpies expressed in kcal/mol to per-molecule eV for quantum chemistry.
Cross-reference calorimetry measurements in kilocalories against particle-physics eV scales.
Convert activation energies in kilocalories to electronvolts for materials science and catalysis.
Check textbook bond energies given in kcal/mol against their per-bond eV equivalents.
Verify thermodynamic data by comparing kcal and eV values across reference sources.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu