Originally Posted by
platyhiker
Assuming you want the HST seam to be on the bias, you take your desired HST size and add 3/4 inch to it. So, in your case you want to cut 3.75 inch squares and use them to make your HSTs. (Details can be found
here.)
sorry, platyhiker, but one should add 7/8" to the finished size. however, I add an inch and then square/trim them up to the desired size.