Electronvolts to Kilocalories per Mole Converter

eV/particle

kcal/mol

↔ Convert kcal/mol to eV/particle instead

Common Conversions

eV/particle	kcal/mol
0.01	0.231
0.025	0.577
0.1	2.306
0.5	11.53
1	23.061
2	46.121
3	69.182
4	92.242
5	115.303
10	230.605
13.6	313.623

Why this conversion matters in chemistry

Photocatalysis crosses this conversion every time band-gap energetics meet thermal-activation barriers. A 3.2 eV TiO₂ anatase band gap is 73.8 kcal/mol — a meaningful number to compare against a typical 20–40 kcal/mol activation energy for a dark catalytic step. The constant of 23.0605 kcal/mol per eV comes from 1 eV × Avogadro's number = 96.485 kJ/mol, divided by 4.184 J/cal. It comes up when computational-chemistry output (in eV or hartree) needs to be in the kcal/mol form experimental thermodynamic data uses.

Formula

kcal/mol = eV × 23.0605

Worked Examples

1 eV = 23.06 kcal/mol

The conversion anchor — useful as a mental factor for any quick scale check.

0.5 eV = 11.53 kcal/mol

A moderate activation-energy barrier, the kind a kinetics study reports.

3.4 eV = 78.4 kcal/mol

About the C–H bond dissociation energy in methane — useful as a strong-bond reference.

0.025 eV = 0.577 kcal/mol

kT at room temperature — the thermal-energy floor below which barriers are easily crossed.

Frequently Asked Questions

How do I convert eV to kcal/mol?

Multiply by 23.0605. So 1 eV becomes 23.06 kcal/mol. The factor is exact through the eV-J definition and Avogadro's number.

Why does this conversion matter?

Computational chemistry outputs energies in eV or hartrees; experimental thermodynamic tables and reaction-kinetics literature use kcal/mol or kJ/mol. Bridging the two units is the routine step before comparing a calculated barrier against a measured one.

What is 1 eV in other energy units?

1 eV = 23.06 kcal/mol = 96.485 kJ/mol = 1.602 × 10⁻¹⁹ J = 8065.5 cm⁻¹. Memorizing two of these gives a fast cross-check on any computational versus experimental energy comparison.

What is kT at room temperature?

At 298 K, kT ≈ 0.0257 eV, equivalent to 0.593 kcal/mol or 2.479 kJ/mol. The figure is the floor of average per-particle thermal energy — barriers comparable to it get crossed routinely; barriers many times larger need catalysis or temperature.