Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law (V=IR). Enter any two values to solve for the rest. Supports mA/A, mV/V, kΩ/Ω units. Visual circuit diagram.
How to Use
1
Enter any two values
Fill in any two of the three fields: Voltage (V), Current (I), or Resistance (R).
2
Select units
Choose the appropriate unit for each value (mV/V, mA/A, Ω/kΩ).
3
Calculate
Click Calculate to solve for the unknown value and see power (P = VI).
4
Read results
View all four values (V, I, R, P) with a visual circuit diagram.
Features
Solves Any Unknown
Enter any two values — V, I, or R — and solve for the third.
Power Calculation
Automatically calculates power P = V × I.
Multiple Units
Supports mV/V, mA/A, Ω/kΩ — converts automatically.
Circuit Diagram
Visual SVG circuit diagram updates with your values.
Frequently Asked Questions
Calculator guides
Recommended Reading
Practical guides matched to this calculator, its inputs, and the result users need to trust.
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