Ohms Law Calculator


Enter 2 values to get the other values and press the Calculate button:


Ohm's law calculation formula

The current I in amps (A) is equal to the voltage V in volts (V) divided by the resistance R in ohms (Ω):

I =
VR

Example

I =
20V
10Ω = 2A

The power P in watts (W) is equal to the voltage V in volts (V) times the current I in amps (A):

P = V × I

Example

P = 20V × 2A = 40W

AC Ohm's law calculator

Enter 2 values of magnitude+phase angle to get the other values and press the Calculate button:

Impedance (Z):
°  = 
Current (I):
°    
Voltage (V):
°    
Power (S):
°  = 

AC Ohm's law calculation formula

The voltage V in volts (V) is equal to the current I in amps (A) times the impedance Z in ohms (Ω):

V(V) = I(A) × Z(Ω) = (|I|×|Z|) ∠ (θI + θZ)

The complex power S in volt-amps (VA):

S(VA) = (|V|×|I|) ∠ (θV - θI)