Free Online Current Calculator

Calculate current from voltage and resistance.

V
Ω
Result Unit
Current: -
Formula: I = V ÷ R

About This Tool

This free online current calculator solves current from voltage and resistance using Ohm’s law. Enter voltage and resistance to calculate current in amps, milliamps, or microamps.

It is useful for circuit design, electronics learning, wiring checks, and quick troubleshooting where you need I = V / R.

Benefits and Use Cases

  • Calculate current from voltage and resistance
  • Estimate circuit amperage quickly
  • Support electronics homework and workshop checks
  • Convert between voltage, resistance, and current units

How to Use

  1. Enter the voltage.
  2. Enter the resistance.
  3. Select the correct units.
  4. Click Calculate.

Frequently Asked Questions

What formula does this current calculator use?

It uses current = voltage / resistance.

What inputs do I need?

You need voltage and resistance.