Ohm's Law Calculator
Solve for voltage, current, or resistance. Power dissipation included.
Known Values
A
Ω
Solving forVoltage (V)
Results
Enter valid component values.
V = I × R
Ohm's Law
Ohm's Law states that the current through a conductor is directly proportional to the voltage across it and inversely proportional to its resistance. It is the foundational relationship for all circuit analysis.
Ohm's Law
V = I × RPower (P = V × I)
P = V × I = I² × R = V² / RKey Points
- Valid for linear (ohmic) resistors at constant temperature
- Non-linear devices (diodes, transistors) do not follow Ohm's Law
- Power dissipated as heat — check maximum ratings
- Double the voltage → double the current (same R)
Common Uses
- Selecting current-limiting resistors
- Calculating voltage drops across components
- Estimating power dissipation and thermal design
- Verifying circuit measurements