🧵 Quilt Binding Calculator

Quilt binding is usually made as double-fold binding. For this style, the standard cutting formula is "finished binding width × 4 + about 1.3cm (0.5in) for seam allowances." For example, if you want a finished width of 1.3cm (about 1/2 inch), cut strips at 4×1.3+1.3 = 6.5cm (about 2.5 inches) wide. This is a widely used approximation in the quilting community — actual results can vary by about ±0.3cm depending on fabric thickness and personal folding habits.

① Perimeter = 2 × (width + height). ② Add an allowance for seam joins and corner miters (typically 20-30cm) to get the total binding length needed. ③ Divide this by your fabric's usable cut width (a bolt of fabric is typically about 106cm/42in wide after trimming the selvage) and round up to get the number of strips needed. ④ Number of strips × strip cut width = the actual fabric length you need to buy. For example, for a 150×200cm quilt, the perimeter is 700cm; adding a 25cm allowance gives 725cm, which needs 7 strips from 106cm-wide fabric, and at a 6.5cm strip width, a total of 45.5cm (about 0.5 yards) of fabric is enough.