DC Ohm’s law calculator
Enter 2 values to get the other values and press the Calculate
button:
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:
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|) ∠ (θI + θZ)
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|) ∠ (θV – θI)
Power factor calculator
Calaulate power factor, apparent power, reactive power and correction capacitor’s capacitance.
- Select phase number.
- Enter real power in kilowatts (kW).
- Enter phase current in amps (A).
- For three phase, select voltage type.
- Enter voltage in volts (V).
- Enter AC frequency in Hertz (Hz) – needed only for capacitance calculation.
- Press the calculate button to get the power factor.
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 ×
VL-L(V) × I(A))
Apparent power calculation:
|S(kVA)| = √3
× VL-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)×VL-L(V)2)
Calculation with line to neutral voltage
Power factor calculation:
PF = |cos φ| = 1000 ×
P(kW) / (3 × VL-N(V) × I(A))
Apparent power calculation:
|S(kVA)| = 3 × VL-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)×VL-N(V)2)
Source: RapidTables, Online Reference & Tools