I would use a strip cutter die in the correct width. After you cut the strips, you can lay the strips crosswise on the die to subcut them into squares. There is probably a Youtube video on how to do this.
I used a Sharpie pen to draw lines on my dies so I know exactly where to line up the fabric. With the strip cutter, I get just 1/4" of waste on each side from the initial stripping.
Different strip cutters cut a different number of strips. The 2.5" strip cutter cuts 3 strips at a time. I layer only one folded fabric at a time to cut strips, so this gives me 3 strips out of an 8" width of fabric. All strips could easily be subcut into 2.5" squares with little waste. I'm thinking the yield would be something like 45 to 50 squares from those 3 strips. From a 36" length of fabric, you could get four 8" cuts -- which would mean 12 strips total (11 strips if you are a little short) or about 180 to 200 squares of 2.5".
All of those calculations would be different with a different strip cutter. The 1.5" strip cutter, for example, cuts 5 strips at a time and probably takes a different rough cut for minimal waste, so the yield would be a different number of squares per yard of fabric.
You can cut squares in a similar manner using the Shape Cut softish ruler and a rotary cutter. I *know* there are Youtube videos that show how to do that!