Joules to Amps Calculator

Summary

This calculator converts energy stored in joules (J) to electric current in amperes (A) when you know the voltage (V) and the duration of current flow (t). It applies the fundamental relationship I = E / (V × t), derived from the definitions of electrical power and energy. Results are useful in circuit design, battery sizing, and energy auditing.

How it works

1. Enter the energy value in joules (J).
2. Enter the voltage in volts (V).
3. Enter the time in seconds (s).
4. Click Calculate — the tool applies I = E / (V × t).
5. The result is displayed in amperes (A) alongside intermediate values.
6. Adjust any input and recalculate instantly.

Use cases

• Determine the average current drawn by a battery-powered device over a known discharge period.
• Size wiring and fuses when the energy budget and supply voltage are known.
• Verify motor or actuator current requirements from rated energy specifications.
• Convert capacitor energy (½CV²) discharge into an equivalent average current.
• Estimate charging current requirements for energy storage systems.
• Cross-check datasheet values when only energy and voltage are listed.
• Academic and homework problems involving electrical energy and charge.
• Quick sanity-check during circuit prototyping.

Frequently Asked Questions