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Electronvolts to Calories Converter
↔ Convert cal to eV instead

Common Conversions

eV cal
1 3.829e-20
10 3.829e-19
100 3.829e-18
1000 3.829e-17
10000000000 3.829e-10
1000000000000000 0.00003829
1000000000000000000 0.03829
10000000000000000000 0.3829
26110000000000000000 1
100000000000000000000 3.829
1e+22 382.9

Why this conversion matters in chemistry

NIST Atomic Spectra Database lists ionization energies in electronvolts — 13.598 eV for hydrogen, 11.260 eV for carbon. Older thermochemistry references list the same quantities as 313.6 kcal/mol for H, with a per-atom value in calories that is dividing by Avogadro's number. Hydrogen's 13.598 eV ionization equals 5.21 × 10⁻¹⁹ cal per atom, the exact same energy in different units. The constant of 3.8293 × 10⁻²⁰ cal per eV comes from 1 eV = 1.602 × 10⁻¹⁹ J and 1 cal = 4.184 J. The setting is straightforward — when atomic-physics spectroscopy meets per-particle thermochemistry.

Formula

cal = eV × 3.8293 × 10⁻²⁰

Worked Examples

1 eV = 3.829 × 10⁻²⁰ cal

The conversion anchor — one electronvolt as a per-particle calorie.

2.611 × 10¹⁹ eV = 1 cal

The reverse anchor — about how many eV make a calorie.

13.6 eV = 5.208 × 10⁻¹⁹ cal

Hydrogen ionization energy per atom, in thermochemistry units.

4 eV = 1.532 × 10⁻¹⁹ cal

A typical C–C bond energy per particle, expressed in calories.

Frequently Asked Questions

How do I convert eV to calories?
Multiply by 3.8293 × 10⁻²⁰. For chemistry-scale work, the per-mole equivalents are usually more useful: 1 eV/particle = 23.06 kcal/mol. Multiply by Avogadro's number first if you need cal/mol.
Is this conversion commonly used directly?
Rarely as written. Chemists convert eV to kcal/mol (× 23.06) or kJ/mol (× 96.485) for direct comparisons against bond and reaction energies. The per-particle calorie form mostly shows up when bridging atomic-physics spectroscopy data and historical per-particle thermochemistry.
What is 1 eV in practical units?
1 eV = 96.485 kJ/mol = 23.06 kcal/mol = 1.602 × 10⁻¹⁹ J = 8065.5 cm⁻¹. Memorizing one or two of these gives a quick sanity check on any energy conversion involving electronvolts.
How many eV is a typical chemical bond?
Bond energies span about 1.5 eV (a weak I–I bond) to 9.8 eV (the N≡N triple bond). Most common single and double bonds sit at 2–5 eV per particle, equivalent to 200–500 kJ/mol.