DC Power Calculator

DC Power Calculator

DC Power


Electric power is the rate of energy consumption in an electrical circuit i.e the electric power is equal to the energy consumption divided by the consumption time.

The electric power associated with a complete electric circuit or a circuit component represents the rate at which energy is converted from the electrical energy of the moving charges to some other form, e.g., heat, mechanical energy, etc.

For a resistor in a DC Circuit the power is given by the product of applied voltage and the electric current.


Formula used for Electric Power calculation is:

Power(watt)[P]= Voltage(v)[V]   *   Current(Amp)[I]

Power (watt)[P]= Voltage² (v²)[V²]   /   Resistance(Ω)[R]

Power(watt)[P] = Current² (A²)[I²]   *   Resistance(Ω)[R]


1. Calculate power of a resistor of resistance 2 Ωand voltage across the resistor is 6 V?

Sol. :

P = V² / R

P = 6²(V²) / 2(Ω)

P = 36 / 2

P = 18 W

Power is 18 Watt

2. The electric current flowing through a resistor is 5 A if power dissipated in the resistor is 35 Watt. Calculate voltage applied across the resistor?

Sol. :

P = V * I

V = P / I

V = 35(W) / 5(A)

V = 7 v

Voltage applied is 7 volt


The standard unit of measurement for Electric Power is Watt i.e. (W)

Below is the conversion chart of various other units of Power