Ohm's Law Calculator
Compute V, I, R and P from any two known values.
Values
Enter any two values — the rest are computed.
Result
Enter any two values.
Ohm's law
V = I·R links voltage, current and resistance. Power follows from any pair: P = V·I = I²·R = V²/R. Enter two values and the calculator fills in the rest — handy for checking LED chains, heaters, or load currents.
Tip: keep R in Ω, I in A, V in V, and P comes out in W directly.