I was trying to figure out the BR needed to generate $25k, using $25 units with about 98% certainty and the risk calculator on this site indicates that one would need 731 units (731x $25= $18225). This seems way too low a BR requirement. Wonder what I am doing wrong?

The calculator asks as follows.

Required Bankroll Given Goal and no Time Constraint

How much do you need to avoid bankruptcy? This is the formula on page 139 solved for bankroll. This is the same as the above calculator, except there is no limit on the number of hands played.
End Result in Units/Goal
Std. Dev. per 100 hands
Win rate per 100 hands
Probability of reaching Goal

I am trying to find the BR needed to generate $25k, playing with a minimum bet of $25 and a spread of 1-7 on DD games and a minimum bet of $10, spread of 1-16 on 6 deck games. I also wanted to find the number of rounds needed under the circumstances.