CRAFTNUMA EDITORIAL · ENGLISH

Check quilt grids and straight-strip binding

A square grid and a binding estimate need different inputs. The first describes the finished top; the second follows the perimeter of the quilt you intend to bind.

Count finished squares first

For a 60 by 80-inch target made from 5-inch finished squares, divide each target dimension by five: 12 across and 16 down. The grid needs 192 squares. With a quarter-inch seam allowance on every edge, each square is cut at 5½ inches. This cutting size includes two allowances in each direction.

For a target width of 61 inches with the same finished squares, rounding up gives 13 across and a 65-inch finished grid. The square planner shows the resulting finished dimensions so that this overshoot is visible. It assumes no sashing or borders; include those in a separate layout before ordering fabric.

Measure the actual binding perimeter

A 60 by 80-inch rectangle has perimeter 2 × (60 + 80) = 280 inches. Add a length allowance you choose for corners, the final overlap and handling. With 10 extra inches, the required assembled strip length is 290 inches. The extra field is editable because different methods need different allowances.

Binding strips can be joined across their ends. Each join may consume some length, so eight strips cut from a 42-inch usable width do not necessarily make 336 usable inches. Enter the actual loss per join for your method rather than assuming every join is free.

Account for the joins explicitly

For n strips of length F and loss J at each join, the joined length is nF − (n − 1)J. There are one fewer joins than strips. To cover a target T when F is larger than J, solve n ≥ (T − J) ÷ (F − J), then round up to at least one strip.

For T = 290 inches, F = 42 inches and J = 2.5 inches, eight strips are needed. Their joined length is 8 × 42 − 7 × 2.5 = 318.5 inches. If each cut strip is 2.5 inches wide, the strips use 20 inches of fabric length across that usable width, or approximately 0.55555556 yards.

Know which construction this model describes

This model uses straight strips cut across a known usable fabric width. It does not estimate continuous bias binding, curved edges, backing or batting. It also does not choose the cut strip width from the desired finished binding width. Those decisions depend on the construction you plan to use.

The perimeter approach is consistent with the Brother binding overview. Our calculator makes the separate extra-length and join-loss assumptions explicit. Check them against your actual joining method and round the purchase up to the supplier’s available increment after reviewing the result.