DC power calculation

⚡ Direct Current (DC) Calculations

Direct Current (DC) is the foundation of many electrical applications. Whether in battery systems, solar technology, or electronic devices – with our DC calculators, you can quickly and precisely calculate all important electrical quantities.

Available Calculations:

Active Power: P = U × I

Calculate electrical power in DC applications

Active Power: P = I² × R

Power calculation via current and resistance

Active Power: P = U² / R

Power calculation via voltage and resistance

Mechanical Power: P = W / t

Calculate mechanical work and power

What is Direct Current?

Direct current refers to a current direction that remains constant and does not alternate. Unlike alternating current, the current always flows in the same direction. Typical applications include batteries, rechargeable batteries, solar cells, and electronic circuits. The calculation of voltage, current, resistance, and power in DC systems follows Ohm's Law and fundamental electrical formulas.

DC Power Calculation
P = U × I

Calculate the supplied electrical power, voltage and current of, for example, DC motors.

P = U × I

💡 Enter the known values – leave the field you want to calculate empty.

✅ Result:

Example Calculation:
A 24 Volt DC motor has a rated current of 33.5 Ampere. What electrical power results from these values?
P = U × I
P = 24 V × 33.33 A
P = 0.8 kW or 800 W

Units of Measurement:
Power P = Kilowatt [kW]
Voltage U = Volt [V]
Current I = Ampere [A]

DC Power Calculation
P = I² × R

Calculate the electrical power, current or resistance.

P = I² × R

💡 Enter the known values – leave the field you want to calculate empty.

✅ Result:

Example Calculation:
A DC motor has a rated current of 25 Ampere and a resistance of 4.8 Ohm. What electrical power results from these values?
P = I² × R
P = (25 A)² × 4.8 Ω
P = 3 kW

Units of Measurement:
Power P = Kilowatt [kW]
Current I = Ampere [A]
Resistance R = Ohm [Ω]

DC Power Calculation
P = U² / R

Calculate the power, voltage or resistance.

P = U² / R

💡 Enter the known values – leave the field you want to calculate empty.

✅ Result:

Example Calculation:
A 24 Volt DC motor has a resistance of 4.8 Ohm. What electrical power results from these values?
P = U² / R
P = (24 V)² / 4.8 Ω
P = 0.12 kW or 120 W

Units of Measurement:
Power P = Kilowatt [kW]
Voltage U = Volt [V]
Resistance R = Ohm [Ω]

Mechanical Power Calculation
P = W / t

Calculate the mechanical power, work or time.

P = W / t

💡 Enter the known values – leave the field you want to calculate empty.

✅ Result:

Example Calculation:
A DC motor performs 4500 Joule of electrical work within 30 seconds. What electrical power results from these values?
P = W / t
P = 4500 J / 30 s
P = 0.15 kW or 150 W

Units of Measurement:
Power P = Kilowatt [kW]
Work W = Joule [J]
Time t = Seconds [s]

Formulas for direct current

  • P = U × I – Power from voltage and current
  • P = I² × R – Power from current and resistance
  • P = U² / R – Power from voltage and resistance
  • P = W / t – Performance from work and time

P is the power in kilowatts (1 kW = 1000 W), U is the voltage in volts, I is the current in amperes, R is the resistance in ohms, W is the work in joules and t is the time in seconds. In any calculator, each of the quantities can be calculated from the others.

Electrical power

Electrical power indicates how much electrical work the electricity does every second - i.e. how much electrical energy is converted into other forms of energy. The unit Watt (W) is named after the Scottish engineer James Watt.

Calculation example P = I² × R

A DC motor has a current rating of 25A and a resistance of 4.8Ω.

P = (25A)² × 4.8Ω
P = 3000W = 3kW