Calculate DC power, current, or voltage by choosing the unknown and entering the two known values using A/mA/kA, V/kV/MV, or W/kW/MW units.

Multiply current by voltage.

Steady DC values. With current into the positive voltage terminal, positive power is absorbed and negative power is delivered.

DC Power Formula

The DC power calculator uses the basic direct-current power relationship between current, voltage, and power.

P = I × V
I = P / V
V = P / I
  • P = power, measured in watts (W), kilowatts (kW), or megawatts (MW)
  • I = current, measured in amperes (A), milliamperes (mA), or kiloamperes (kA)
  • V = voltage, measured in volts (V), kilovolts (kV), or megavolts (MV)

To calculate power, enter current and voltage. The calculator multiplies amps by volts and returns the result in your selected power unit.

To calculate current, enter power and voltage. The calculator divides power by voltage and returns the result in your selected current unit.

To calculate voltage, enter power and current. The calculator divides power by current and returns the result in your selected voltage unit.

All calculations are converted through base units first: amps, volts, and watts.

DC Power Unit Conversions

Quantity Unit Base-unit equivalent
Current 1 mA 0.001 A
Current 1 kA 1,000 A
Voltage 1 kV 1,000 V
Voltage 1 MV 1,000,000 V
Power 1 kW 1,000 W
Power 1 MW 1,000,000 W

Common DC Power Values

Current Voltage Power
1 A 5 V 5 W
2 A 12 V 24 W
10 A 24 V 240 W
50 A 48 V 2,400 W or 2.4 kW

DC Power Examples

Example 1: Calculate power

You have a DC circuit with 12 V and 3 A.

P = I × V
P = 3 × 12 = 36 W

The power is 36 W.

Example 2: Calculate current

You have a 240 W DC load connected to a 24 V supply.

I = P / V
I = 240 / 24 = 10 A

The current is 10 A.

DC Power Calculator FAQ

What is DC power?

DC power is electrical power in a direct-current circuit. In a DC circuit, current flows in one direction. Power is found by multiplying voltage by current, so a 12 V circuit carrying 5 A uses 60 W.

Is DC power the same as AC power?

Not always. For simple DC calculations, power is voltage times current. AC power can require extra values such as power factor, RMS voltage, RMS current, and phase angle. This calculator is for DC power calculations, not AC apparent or real power calculations.

Why do I need to enter exactly two values?

The formula has three variables: power, current, and voltage. Choose the unknown and enter the other two. An inverse solve requires a nonzero voltage or current divisor: a zero divisor with zero power gives no unique answer, and a zero divisor with nonzero power gives no solution.