Design and Size A Quilt

Assumptions Used in the Calculators

  • A usable fabric width of 40″
  • Binding strips are cut 2-1/2″ x WOF

Sashing and Cornerstones

For sashing, the results will give two options: sashing without cornerstones and sashing with cornerstones.

The diagrams show the sashing and cornerstone placement options for these calculations.

sash and cornerstones
Sashing With Cornerstones
horizontal sash without cornerstones
Sashing Without Cornerstones

For sashing without cornerstones, the horizontal sashings are stitched together end-to-end then cut to the width needed.


Borders are calculated under the assumption that the side borders are cut and sewn to the quilt top first. The top and bottom borders are cut and sewn after the side borders are attached.

For crosswise cuts, all strips are stitched together end to end to make one long strip.

  1. Measure the length of the quilt top. Cut 2 strips to this length. Attach side borders.
  2. Measure the width of the quilt top. Cut 2 strips to this length. Attach the top and bottom borders.

For lengthwise cuts, press the center crease along the lengthwise grain. 


To calculate the amount of backing fabric, the software adds 3” to each side of the quilt top which adds 6” to the total width and 6” to the total length.

44″ Wide Fabric

The yardage for the backing fabric is cut into equal lengths. The lengths are stitched together along the selvage edges. This results in vertical seams in the backing. This works for directional and non-directional backing fabrics.

108″ Wide Fabric

If the quilt finished length is 100″ or less, the backing selvages run along the top and bottom of the quilt top as shown.

If the quilt finished length is larger than 100″, the selvage runs along the sides of the quilt top.

For quilt tops that are larger than 100″ wide and 100″ long you will receive the message “Out of range.” These quilt sizes require backing fabric to be seamed.

Sizing A Quilt Revised 3-03-29-2024
Sizing A Quilt


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Happy quilting!

2 responses to “Design and Size A Quilt”

  1. Darrelllena J Payne Avatar
    Darrelllena J Payne

    Hello Carol,
    Thank you for all you have done to help me get it right. The newest block that I’ve been working on has really worked my brain. I’m usually using large(r) blocks but this one has had me scratching my head, lol. I discovered the maker of it just last night after making 60 of these 8.75″ sq…makeup of my own calculations.
    I found a picture of another quilters pieced up in red, white, & blue on Pinterest
    The original designer is Bonnie Hunter and the pattern that eluded me for years is the “Diamond Tile” which was published in QuiltMakers Mag. I’ve yet to find the actual pattern for her design.
    Your calculator above has been extremely beneficial in helping me to figure out my borders. Thank you again for all your hard work in helping me get there.

    1. Carol Thelen Avatar

      Hello Darrellena, I am so happy that the calculators have helped you solve a mystery. I know how frustrating it is to know what you want but can’t seem to find the last little thing. Thank you so much for your kind comments!.

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