# Ohm's Law Calculator

> Calculate voltage, current, resistance, or power using Ohm's law. Free ohms law calculator with the formula shown - runs entirely in your browser, no signup.

- **Canonical URL:** https://boringtoolskit.com/ohms-law-calculator/
- **Category:** Everyday Calculators
- **Evidence level:** authored-methodology
- **Reviewed:** August 2026
- **Last verified:** 2026-10-12
- **Privacy:** Inputs and results stay in this browser unless the page clearly labels an external request.

## How it works

V = I x R (voltage = current x resistance); rearranged to I = V / R or R = V / I for whichever pair you enter.

## Worked example

12 A through 4 ohms: V = 12 x 4 = 48 V.

## Sources

- [Calculation methodology and verification standard](/methodology/)

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