How many architectural shingle bundles per square?

33. There are 3 bundles per square. A square is 100 square feet.

33 it takes 3 bundles to cover a square. A square is 10'x10'

3 bundles per square on average. So 3.5 square is 10 bundles.

The number of bundles can vary due to shingle weight and size. Normally three or four per square. Check the package information for specifications.

For 644 square, a square is 100 square feet. 3 bundles to a square so 3x644=1,932 bundles. I imagine your question is how many bundles for 644 square feet. That's 20 bundles plus 2 for the starter...