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Voltage Calculator

Voltage from current and resistance, V = IR.

Introduction

Voltage Calculator — Voltage from current and resistance, V = IR. Enter Current (A), Resistance (Ω) to get an instant, accurate result.

Formula

Voltage is calculated using Ohm's Law: V = I × R, where I is the electric current flowing through a conductor and R is its resistance.

Step-by-step

  1. Enter the Current (A).
  2. Enter the Resistance (Ω).
  3. Click Calculate to see your result instantly.

Real-world example

Example: With Current (A) = 2, Resistance (Ω) = 100, the Voltage Calculator gives Voltage V: 200.

Frequently Asked Questions

What is Ohm's Law?
Ohm's Law, named after German physicist Georg Ohm, describes the relationship between voltage, current, and resistance in a circuit: V = IR.
What units does this calculator use?
Enter current in amperes (A) and resistance in ohms (Ω) to get voltage in volts (V), the standard SI units for electrical quantities.
Does Ohm's Law apply to all electrical components?
It applies precisely to ohmic (linear) components like standard resistors. Non-ohmic components such as diodes and transistors have a voltage-current relationship that is not linear.
What inputs does the Voltage Calculator need?
You'll need to provide: Current (A), Resistance (Ω). All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.
How accurate is the Voltage Calculator?
The Voltage Calculator applies the formula exactly as calculated — Voltage is calculated using Ohm's Law: V = I × R, where I is the electric current flowing through a conductor and R is its resistance. — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.
Is the Voltage Calculator free to use?
Yes, the Voltage Calculator is completely free, requires no signup, and runs instantly in your browser.

About the Voltage Calculator

The Voltage Calculator uses a real, verifiable formula — Voltage is calculated using Ohm's Law: V = I × R, where I is the electric current flowing through a conductor and R is its resistance. — so results are accurate every time, not an approximation.