Volts to Joules Calculator

Convert Volts to Joules with the formula, a worked example and a table of typical values. Working shown step by step.

Voltage 12 V, charge 2 C gives

24 J

Estimate only. Not engineering or safety advice. Check the result against the applicable standard and the equipment data, and have a competent engineer review it before it is relied on. Terms of use.

Open in the calculator with these values

Formula

E = Q × V (1 eV = 1.602176634×10⁻¹⁹ J, the energy of one elementary charge e through 1 V)

Worked example

Input	Value
Voltage	12 V
Charge	2 C

E = Q × V = 2 C × 12 V = 24 J
In electronvolts: 1.498e20 eV; charge is 1.248e19 e

Typical values

Voltage (V)	Energy (J)
1.5	3
5	10
12	24
24	48
230	460

Other inputs are the same as in the worked example above.

Assumptions

Magnitudes only: signs and direction are ignored
Charge moves through the whole potential difference
Elementary charge e = 1.602176634×10⁻¹⁹ C (exact SI value)

For eV to volts, enter the energy in eV and the charge in e (for one electron, 1 e). The volts figure then equals the energy in eV divided by the number of charges. This is the electrostatic relation, not a circuit power calculation.

Frequently asked questions

How do I convert Volts to Joules?

E = Q × V (1 eV = 1.602176634×10⁻¹⁹ J, the energy of one elementary charge e through 1 V). Worked example: Voltage 12 V, charge 2 C gives 24 J.

What do I need to enter?

Enter energy, voltage and charge. Leave blank the value you want to find, and the form solves for it. Change the unit of a value with its selector and the result stays the same.

How are volts and joules related?

One volt is one joule per coulomb, so energy in joules = charge in coulombs × voltage in volts.

How accurate are the results?

Every figure comes from the same tested engine as the Elecmetric calculators and is meant for estimating. Check design values against the standard and the equipment data you work to.

Next steps in a design: kW to kWh Energy Unit Converter Ohm's Law (V, I, R, P)
Opposite direction: Joules to Volts
Also see: eV to Volts Volts to eV Volts to Ohms Ohms to Volts
Formula guides: Capacitor Formulas: Energy and RC Time Constant Coulomb’s Law Calculator Energy Converter
All 78 conversions Joules, Volts, Charge and eV (any two) in Elecmetric