Power4all

Current Calculator

Instantly calculate current using voltage, resistance, and power. Supports DC, AC single-phase, and AC three-phase.

DC Current

AC Single-Phase

AC Three-Phase

DC Current Calculator

I = V / R (Current = Voltage ÷ Resistance)
I = P / V (Current = Power ÷ Voltage)
I = √(P / R) (Current = Square root of Power ÷ Resistance)

Voltage (V):

Resistance (Ω):

Power (W):

Enter any two values to calculate current

AC Single-Phase Current Calculator

I = P / (V × PF) (Current = Power ÷ (Voltage × Power Factor))
I = V / R (Current = Voltage ÷ Resistance)

Voltage (V):

Power (W):

Power Factor (PF):

Resistance (Ω):

Enter required values to calculate current

AC Three-Phase Current Calculator

I = P / (√3 × V × PF) (Current = Power ÷ (√3 × Voltage × Power Factor))
I = V / R (Current = Voltage ÷ Resistance)

Line Voltage (V):

Total Power (W):

Power Factor (PF):

Resistance (Ω):

Enter required values to calculate current

Understanding Current Equations

Electric current (I) is the flow of electric charge in a circuit. You can calculate it using three equations, depending on which quantities you know:

I = V / R - Current from voltage and resistance
I = P / V - Current from power and voltage
I = √(P / R) - Current from power and resistance

Example 1: Using I = V / R

A circuit has a voltage of 12 V and a resistance of 6 Ω. What is the current?

Solution: I = 12 / 6 = 2 A

Example 2: Using I = P / V

A device uses 60 W of power at 12 V. What is the current?

Solution: I = 60 / 12 = 5 A

Example 3: Using I = √(P / R)

A resistor has a resistance of 16 Ω and dissipates 64 W. What is the current?

Solution: I = √(64 / 16) = √4 = 2 A

Example 4: AC Single-Phase

A 230V device with 2000W power and PF=0.8. What is the current?

Solution: I = 2000 / (230 × 0.8) = 10.87 A

Example 5: AC Three-Phase

A 400V three-phase system, 5000W load, PF=0.9. What is the current?

Solution: I = 5000 / (√3 × 400 × 0.9) = 8.02 A