Free Online Voltage Calculator

Calculate voltage from current and resistance.

A
Ω
Result Unit
Voltage: -
Formula: V = I × R

About This Tool

This free online voltage calculator solves voltage from current and resistance using Ohm’s law. Enter current, resistance, choose the units, and calculate voltage instantly.

It is useful for electronics learning, circuit checks, troubleshooting, and quick electrical calculations where you need V = I * R.

Benefits and Use Cases

  • Calculate voltage from current and resistance
  • Support basic electronics and electrical coursework
  • Check circuit values before building or troubleshooting
  • Convert between common current, resistance, and voltage units

How to Use

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

Frequently Asked Questions

What formula does this voltage calculator use?

It uses voltage = current * resistance.

What inputs do I need?

You need current and resistance.