Ohm's Law Calculator
Enter any two values — voltage, current, resistance, or power — to calculate the remaining two electrical quantities.
Type into any 2 fields. The calculator will automatically lock those as your inputs and solve the other 2 fields.
Input
Input
Calculated
Calculated
Calculated Results (Base Units)
Voltage12 V
Current2 A
Resistance6 Ω
Power24 W
Ohm's Law Formula WheelHighlights show active formulas used in the calculation
Active Equations
R = V / I
P = V * I
How to use Ohm's Law
Ohm's Law states that the voltage across a resistor equals the current through it multiplied by its resistance (V = I × R). Enter any two known values and the calculator solves for the third. Power (P = V × I) is shown as a bonus result — it's the energy consumed or delivered per second, measured in watts.
Private & free — this tool runs entirely in your browser.
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