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Ohms Law Calculator

Enter your values below to get the result first, then scroll for the full explanation and guidance.

Step 1 • Add values

Use the calculator

Enter your values below to generate an instant result. You can update the inputs at any time to compare different scenarios.

Example: 2 A through 5 ohms gives 10 V.

Results refresh instantly as values change.

Voltage

10 VOhm's law: V = I × R

Voltage: 10 V (Ohm's law: V = I × R)

Multiply current in amperes by the known resistance in ohms. For a voltage-drop estimate, enter total path resistance.

Electrical values

Multiply current in amperes by the known resistance in ohms. For a voltage-drop estimate, enter total path resistance.

Result snapshot

A quick visual read of the values behind this result.

Current2 A
Resistance5 ohms

Recommended next checks

  • →Use measured or otherwise established resistance; this tool does not determine wire resistance.
Current
2 A
Resistance
5 ohms

Try different values to compare results.

Enter current and known resistance to calculate voltage using Ohm's law. This version solves V = I x R only.

Inputs and units stated

Formula shown

Scope limits explained

Table of Contents

6

About Ohms Law Calculator

Ohms Law Calculator helps you work through the main numbers for this topic quickly with a simple input flow and an instant result.

Use the calculator result as a practical starting point, then review the explanation and assumptions on the page if you want more context.

Ohm's law formula

Voltage (V) = current (A) x resistance (ohms). Two amperes and five ohms give ten volts for an ohmic element.

Formula explained

Ohm's law

Find voltage from current in amperes and resistance in ohms using Ohm's law.

Formula

Voltage = current (A) x resistance (ohms)

How the result is built

1Enter the labelled values using the stated units.
2Apply Voltage = current (A) x resistance (ohms).
3Read the result alongside the page assumptions and scope limits.

Example

Example: 2 A through 5 ohms gives 10 V.

Assumptions

  • Voltage = current x resistance for an ohmic element.
  • This tool does not size wiring or certify electrical safety.

Source basis

  • OpenStax Physics, Ohm's law

FAQ

Common questions

No. This input flow calculates voltage from current and resistance; those other quantities need different known inputs.

Trust and notes

Assumptions and important notes

This calculator is designed to give a fast estimate using the method shown on the page. Results are most useful when your inputs are accurate and the tool matches your situation.

Use the result as guidance rather than a final diagnosis or professional decision. If the result could affect health, legal, financial, or compliance decisions, verify it with a qualified source where appropriate.

  • Voltage = current x resistance for an ohmic element.
  • This tool does not size wiring or certify electrical safety.

Method

Ohm's law

Last reviewed

October 12, 2026