⚡ Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law formulas
Input Values
Results
Voltage
-- V
Current
-- A
Resistance
-- Ω
Power
-- W
Formula Used
Enter any two values to see the calculation
Steps will appear here when calculation is performed
📚 Ohm's Law & Power Formulas
Ohm's Law
V = I × R
I = V / R
R = V / I
Power Formulas
P = V × I
P = I² × R
P = V² / R
Where: V = Voltage (Volts), I = Current (Amperes), R = Resistance (Ohms), P = Power (Watts)
❓ Frequently Asked Questions
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points. It is expressed as V = I × R, where V is voltage, I is current, and R is resistance.
Simply enter any two known values (voltage, current, resistance, or power) and the calculator will automatically compute the remaining values using Ohm's Law and power formulas.
The calculator supports multiple units: Volts (V, mV, kV) for voltage, Amperes (A, mA, μA) for current, Ohms (Ω, kΩ, MΩ) for resistance, and Watts (W, mW, kW) for power.
No, Ohm's Law applies primarily to resistive components. It does not apply to non-linear components like diodes, transistors, or other semiconductors where the voltage-current relationship is not linear.
Power can be calculated using three formulas: P = V × I, P = I² × R, or P = V² / R. The calculator will automatically use the appropriate formula based on your known values.
This calculator is designed for DC circuits and resistive AC circuits. For reactive AC circuits with capacitors or inductors, you would need impedance calculations which involve complex numbers.
Yes, the calculator automatically saves your recent inputs and settings in your browser's local storage for up to 30 days for your convenience.
This calculator provides accurate results for educational and basic engineering purposes. For critical professional applications, always verify results and consult with qualified electrical engineers.
⚠️ Disclaimer
This calculator is provided for educational and reference purposes only. The results should not be used for critical electrical engineering applications without verification by qualified professionals. Always follow proper electrical safety procedures and consult with licensed electricians for actual electrical work. The developers are not responsible for any damages or injuries resulting from the use of this calculator.