Reconstitution maths is simple once you separate the three quantities involved: the amount of compound in the vial (mg), the volume of bacteriostatic water you add (ml), and the resulting concentration (mg/ml).
Concentration is just compound divided by water. From there you can work out the volume that corresponds to any measured amount. Our Research Calculator does this for you and shows the result on a U-100 scale — for laboratory measurement reference only.