Im looking to do SMASH for next brew is there a rule of thumb for lbs of malt per gal of finished vol?
It's no different than any other recipe. Grain amount depends on your target batch size, OG and overall efficiency.
Ballpark, about 10 lbs of grain will net about 5 gallons of 1.050 wort.
ok thanks. i ended up trying out beersmith app its pretty nice tool.