Prima rakeback and Calculation

[Emwi]

Just received rakeback on prima. Is there avg comntr rakeback or weighted rakeback on prima?

Ive also tried surfing and testing out different rakeback calulators. But they all differ , any ideas where i can find a good rakeback calculator that i can trust?

Would i be calculating correctly if i did it this way:
RAKE*AVGPOT*HANDS/PLAYERSINHAND

0.05 * 8 ( FL 1/2 )* 230 ( 1000 raked hands / 23%VPIP that i have ) / 3 ( avg players / hand ).

Is this correct? Or should i calculate with 1000 hands ? or how do you do these calculations?