VA to watts calculation formula
P(W) = S(VA) × PF
The real power P in watts (W) is equal to the apparent power S in volt-amps (VA), multiplied by the power factor PF.
W = VA x PF
watt = volt-amp x PF
Power (S) = 4500VA
PF = 0,7
Power (P) = 4500VA x 0,7 = 3150W