I am looking for a free calculator that will allow give me ranges for a given MOA offset. (rather than the MOA offset for a given range). Is there a easily available one that will do that?

NM found it

Curious, are you attempting to back into a velocity or BC measurement?

I was looking for the exact yardages for the ticks on a BDC reticle from a 200yd zero. In the end I just ran the drop table in 10 yd increments, not perfect but close enough.