Convert Volts to Joules (J) instantly. Our free online calculator handles voltage to energy conversions using charge or capacitance. Includes formulas and reference tables.
How to Convert Volts to Joules
Converting Volts to Joules requires an understanding of what both units represent. Volts (V) measure electrical potential difference, while Joules (J) measure energy. To find the energy in Joules, you must also know the amount of electric Charge or the Capacitance involved in the circuit.
The Formulas
Depending on your known variables, use one of the two following electrical energy formulas:
1. Using Charge (Coulombs):Energy (J) = Potential (V) × Charge (Q)
2. Using Capacitance (Farads):Energy (J) = ½ × Capacitance (C) × Potential (V)²
Volts to Joules Conversion Table
This table shows the resulting energy in Joules when various voltages are applied to a fixed charge of 1 Coulomb or a capacitance of 1000µF (0.001F).
| Voltage (V) | Energy at 1 Coulomb | Energy at 1000µF |
|---|---|---|
| 5 Volts | 5 J | 0.0125 J |
| 12 Volts | 12 J | 0.072 J |
| 120 Volts | 120 J | 7.2 J |
| 240 Volts | 240 J | 28.8 J |
Important Definitions
Volt (V): The unit of electrical potential. One volt is defined as the potential difference that will impart one joule of energy per coulomb of charge that passes through it.
Joule (J): The standard unit of energy in the International System of Units. In electricity, it represents the work done to move an electric charge through an electric potential difference.
Coulomb (Q): The unit of electric charge. It is the amount of electricity transported in one second by a current of one ampere.
Capacitance (C): The ability of a component (a capacitor) to collect and store energy in the form of an electrical charge, measured in Farads (F).
Why Use This Converter?
This conversion is vital for electrical engineers designing power supplies and students studying electromagnetism. It allows you to calculate how much total work a battery can perform based on its potential or how much energy is stored within the electric field of a charged capacitor.