DC Ohm’s law calculator

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

	Resistance:	R	=		ohms (Ω) kilo-ohms (kΩ) mega-ohms (MΩ)
	Current:	I	=		micro-amps (μA) milli-amps (mA) amps (A) kilo-amps (kA) mega-amps (MA)
	Voltage:	V	=		micro-volts (μV) milli-volts (mV) volts (V) kilo-volts (kV) mega-volts (MV)
	Power:	P	=		micro-watts (μW) milli-watts (mW) watts (W) kilo-watts (kW) mega-watts (MW)

DC calculation

Voltage (V) calculation from current (I) and resistance (R):

V_(V) = I_(A) × R_(Ω)

Complex power (S) calculation from voltage (V) and current (I):

P_(W) = V_(V) × I_(A) = V
²_(V) / R_(Ω) = I
²_(A) × R_(Ω)

AC Ohm’s law calculator

Enter 2 values 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	∠		°	=

AC calculation

The voltage V in volts (V) is eqaul 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) is equal to the voltage V in volts (V) times the current I in amps (A):

S_(VA) = V_(V) × I_(A) =
(|V|×|I|) ∠ (θ_V – θ_I)

 Power factor calculator

Calaulate power factor, apparent power, reactive power and correction capacitor’s capacitance.

1. Select phase number.
2. Enter real power in kilowatts (kW).
3. Enter phase current in amps (A).
4. For three phase, select voltage type.
5. Enter voltage in volts (V).
6. Enter AC frequency in Hertz (Hz) – needed only for capacitance calculation.
7. Press the calculate button to get the power factor.

	Select phase #:	Single phase Three phase
	Enter real power in kilowatts:		kW
	Enter current in amps:		A
	Select voltage type:	Line to line voltage Line to neutral voltage
	Enter voltage in volts:		V
	Enter frequency in hertz:		Hz
	Power factor result:
	Apparent power:		kVA
	Reactive power:		kVAR
	Correction capacitor:		μF

The power factor correction capacitor should be connected in
parallel to each phase load.

Single phase circuit calculation

Power factor calculation:

PF = |cos φ| = 1000 ×
P_(kW) / (V_(V) ×
I_(A))

Apparent power calculation:

|S_(kVA)| = V_(V) × I_(A) / 1000

Reactive power calculation:

Q_(kVAR) = √(|S_(kVA)|² – P_(kW)²)

Power factor correction capacitor’s capacitance calculation:

C_(F) = 1000 × Q_(kVAR)
/ (2πf_(Hz)×V_(V)²)

Three phase circuit calculation

For three phase with balanced loads:

Calculation with line to line voltage

Power factor calculation:

PF = |cos φ| = 1000 ×
P_(kW) / (√3 ×
V_L-L(V) × I_(A))

Apparent power calculation:

|S_(kVA)| = √3
× V_L-L(V) × I_(A) / 1000

Reactive power calculation:

Q_(kVAR) = √(|S_(kVA)|² – P_(kW)²)

Power factor correction capacitor’s capacitance calculation:

C_(F) = 1000 × Q_(kVAR)
/ (2πf_(Hz)×V_L-L(V)²)

Calculation with line to neutral voltage

Power factor calculation:

PF = |cos φ| = 1000 ×
P_(kW) / (3 × V_L-N(V) × I_(A))

Apparent power calculation:

|S_(kVA)| = 3 × V_L-N(V) × I_(A) / 1000

Reactive power calculation:

Q_(kVAR) = √(|S_(kVA)|² – P_(kW)²)

Power factor correction capacitor’s capacitance calculation:

C_(F) = 1000 × Q_(kVAR)
/ (3×2πf_(Hz)×V_L-N(V)²)

Source: RapidTables, Online Reference & Tools