Finished sizes and cut sizes have different jobs
Block and border calculators start with finished sizes and add the seam allowance needed for the cuts. The square cutting calculator uses the cut square size directly. Backing and batting start with the measured quilt top and add the overhang you choose. Read the field label before adding another allowance.
Binding is measured after the strips are joined
The binding target is twice the quilt width plus twice the height, with your finishing tail added. Diagonal joins use one strip width per join in this plan; straight joins use two seam allowances. The calculator adds enough strips to reach the target after those joins. It covers straight-grain strips, not bias-cut binding.
Backing panels lose width at each seam
The backing plan adds overhang to the top, then finds how many panels cover the target span. Each panel join uses a seam allowance from both adjoining pieces. Panel direction determines which quilt dimension the strips need to cover. Rotation is checked against the fabric-direction settings you choose.
Cutting length comes before shopping yardage
Raw fabric length covers the planned cuts. In the binding tool, any extra-fabric percentage is added next. The purchase amount is then rounded up to the shop increment you select. Twenty inches of fabric, for example, rounds up to ⅝ yard when the shop sells in ⅛-yard cuts.
A drawing is a guide to the list
The diagrams show a sample of the cuts, with labeled sizes and counts. They aren't drawn to scale and aren't full-size templates. The tools don't arrange every piece for the lowest possible fabric use, match printed motifs or share leftovers between projects. Use the cutting diagram guide to read the list, and check the actual fabric before cutting.
For a specific calculation, open the relevant calculator or block tool. Its notes explain the cuts and allowances used in that plan.