Ohm's Law Calculator

Calculate voltage, current, resistance, and power.

Enter Any Two Values

Enter at least two values to calculate the others.

Voltage (V)

V

Volts

Current (I)

A

Amps

Resistance (R)

Ω

Ohms

Power (P)

W

Watts

Ohm's Law Formulas

Voltage (V)

V = I × R

V = P / I

V = √(P × R)

Current (I)

I = V / R

I = P / V

I = √(P / R)

Resistance (R)

R = V / I

R = V² / P

R = P / I²

Power (P)

P = V × I

P = V² / R

P = I² × R

Calculated Values

Voltage (V)12 V

Current (I)3 A

Resistance (R)4 Ω

Power (P)36 W