Ohm's Law Calculator
Solve for voltage, current, resistance or power.
About this tool
Ohm's Law relates voltage, current and resistance in an electrical circuit: V = I × R. Pick which quantity you want to solve for, enter the other two, and this also computes power (P = V × I).
Key Features
- Solve for voltage, current or resistance
- Also calculates power
- Standard Ohm's Law and power formulas
How to Use
- Choose which value to solve for.
- Enter the other two values.
- Click Calculate.
Benefits
- Check basic circuit calculations
- Useful for electronics coursework and hobby projects
- See power draw alongside the solved value
Frequently Asked Questions
Standard SI units: volts (V), amps (A) for current, and ohms (Ω) for resistance. Power is calculated in watts (W).
A resistance of exactly 0 (a short circuit) would mean infinite current for any nonzero voltage — the calculator blocks this rather than showing an infinite or undefined result.