🧵 Quilt Calculator
Enter your quilt dimensions and block size to find how many blocks you need and how much fabric to buy.
Planning a pieced quilt
Before piecing a quilt top, it helps to know how many blocks fit your target quilt size and roughly how much fabric you’ll need for the top, backing, and batting.
The formula
This calculator divides your quilt’s width and height by your chosen finished block size (rounding up) to find Blocks Across × Blocks Down = Total Blocks. It estimates top fabric yardage from the total quilt area plus a 10% seam and cutting buffer, and estimates backing fabric using the quilt size plus an 8-inch overhang on each dimension (a common quilting allowance for basting and quilting shrinkage), divided by a standard 44-inch fabric width.
This is a simplified single-fabric estimate — multi-fabric designs, sashing, borders, and directional prints will change actual yardage. Always buy a bit extra fabric as a buffer. For general craft planning purposes.