Ohms Law Calculator

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

Voltage (V)

microvolts (μV) millivolts (mV) volts (V) kilovolts (kV) megavolts (MV)

Current (I)

microamps (μA) milliamps (mA) amps (A) kiloamps (kA) megaamps (MA)

Resistance (R)

ohms (Ω) kiloohms (kΩ) megaohms (MΩ)

Power (P)

microwatts (μW) milliwatts (mW) watts (W) kilowatts (kW) megawatts (MW)

  = Calculate × Reset

Calculation

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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):

Example

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):
	Ω kΩ MΩ	∠		°	=
Current (I):
	μA mA A kA MA	∠		°
Voltage (V):
	V kV MV	∠		°
Power (S):
	VA kVA MVA	∠		°	=
= Calculate × Reset

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|) ∠ (θ_I + θ_Z)

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

S_(VA) = (|V|×|I|) ∠ (θ_V - θ_I)