Half Square Triangle Calculator: Precise HST Fabric Cutting Tool

Calculate Your Half Square Triangle Dimensions

inches

Discover the ultimate Half Square Triangle (HST) Calculator for quilters. This tool simplifies determining fabric dimensions for perfect HST blocks, whether you need finished size, cut fabric, or block size. Achieve precision in your quilting projects with ease!

Formula:

To calculate the required fabric square size for Half Square Triangles (HSTs), we use a standard quilting formula:

C = W + 0.875

  • C = Side length of the initial fabric square to cut (in inches)
  • W = Desired finished width of the Half Square Triangle block (in inches)
  • 0.875 = Standard seam allowance for this HST construction method (7/8 inch)

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