Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law and Watt's Law.
Enter any two values to calculate the other two:
Voltage (V)
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Current (A)
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Resistance (\u03a9)
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Power (W)
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Ohm's Law Triangle: V / (I \u00d7 R) \u00a0\u00a0\u00a0 Watt's Law: P / (V \u00d7 I)
How It Works
Ohm's Law: V = I \u00d7 R (Voltage = Current \u00d7 Resistance). Watt's Law: P = V \u00d7 I (Power = Voltage \u00d7 Current). From these two equations, if you know any two values, the other two can be calculated.
About this Calculator
The Ohms Law is a free, easy-to-use tool for various calculations. Simply enter your values and get instant, accurate results — no signup, no ads, no tracking. All calculations run locally in your browser, so your data stays completely private.
Privacy Note: All calculations are performed locally in your browser. No data is ever sent to a server or third party.