washed yeast starters

looking at the mrmalty pitching from slurry calculator, it seems that a half cup of washed fairly pure yeast is more than enough to pitch into most any beer. I set the concentration to 4 and the non-yeast percentage to 4 and the viability to 80%. If I'm calculating correctly, it looks like with these settings 1/4 cup of solid yeast is about the equivalent to 2 smack packs. So I was thinking about calculating the starter for 2 smack packs and guestimating about a 1/4 cup of yeast into the starter. Is this reasoning sound?

bump

That sounds fine to me. I usually use mrmalty as a helpful tool to get near the right pitching level...not a perfect science. If anything, it's better to overpitch by a little, than to underpitch.

cool, I definitely guestimated a little bit over. It felt better to try and get close to 2 smack packs worth than just dump in all the yeast in the jar