Free Ohm's Law Calculator

Enter any two of voltage, current, resistance, and power — the other two are solved instantly using Ohm's law (V=IR) and the power equation (P=VI).

Runs in your browserNo sign-up, no pop-upsNo login requiredFree forever
V
A
Ω
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Enter any two values and the other two are solved automatically

💡 Ohm's law: V = I × R. Power adds P = V × I. Knowing any two lets you derive the rest — handy for sizing resistors, checking LED current, or working out heat dissipation.

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How It Works

1
Enter
Enter your text or data.
2
Process
Processed instantly in your browser. No server, no waiting.
3
Download
Save your result. Nothing is stored.

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Completely free — no hidden costs, ever
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Works on any device — phone, tablet, desktop
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Loads fast, with no installation needed

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