Equilateral Triangle Quilt Calculator

The Equilateral Triangle Quilt Calculator is designed to help quilters understand how large their pieced quilt top made from equilateral triangles (60° triangles) will become. Instructions and graphics explaining the inputs and outputs are located below the calculator.

The calculator is an Excel file hosted by Microsoft Office Online and may take a few moments to load. You may interact with the Excel file here on my website, or you may choose to download the Excel file. Instructions on how to download and save the Equilateral Triangle Quilt Calculator (which contains instructions within the file) to your computer are at the bottom of the instructions.

Instructions

  • Blue text / blue cells are required input
    • Click on desired input cell and type in numeric value. Clicking away or pressing Enter will update the output fields.
  • Red text is output
    • If you accidentally type over the red numbers, a message will appear notifying you that those cells are protected and the spreadsheet will update back to the correct formula and output.

Input

Height of Strip
Height of Strip
  • The Height of Strip input is the dimension of your equilateral (60°) triangles from the top point to the base prior to piecing. This dimension is typically noted as 5″ x WOF (width of fabric) in cutting instructions (in this case, the input would be 5).
Example Top: 16 Across, 12 Down
Example Top: 16 Across, 12 Down
  • An example of a 16 across by 12 down quilt top is shown above. If you are using the tool to determine the number of triangles to cut for your quilt top, multiply the number across by the number down (16 x 12) to find the total number of triangles needed for your quilt top (192 in this example).

Output

Edge Finishing: Piece Half Triangles
Edge Finishing: Piece Half Triangles
  • When piecing equilateral triangle quilt tops, you may choose to piece in half triangles at the beginning and end of each row. If you choose to piece in half triangles, the size of your pieced quilt top is noted in the “Edge Finishing: Piece Half Triangles” output section.
Edge Finishing: Trim
Edge Finishing: Trim
  • You may also choose to trim the quilt back to the points or leave the edges non-square. If you choose one of these piecing options, the size of your pieced quilt top is noted in the “Edge Finishing: Trim” output section.
Download Button
Download Button

At the bottom of the calculator at the top of the page, you may download a copy of the Excel file by clicking on the indicated icon.

Questions? Comments? Concerns? Requests?

Please leave a comment or email me at jetgirl8 (at) gmail (dot) com. Especially let me know if you have requests for similar tools!