How to Calculate Fabric Yardage for Quilts

  • 01 of 03

    Easy Steps to Calculate Quilt Yardage

    How to Figure Yardage for Quilts
    Learn to Figure Yardage for Quilts. Janet Wickell

    Calculating how much fabric you need to make a quilt is easy once you understand the basics. Try this step-by-step tutorial to calculate yardage for your next quilting project.

    Choose a Quilt Size and Design First

    You'll need to make some decisions before you can calculate how much fabric is needed for a quilt:

    • How large must the quilt be?
    • If you need help with quilt size, refer to my chart of standard mattress sizes.
    • Decide how much of the quilt top will be made up of quilt blocks, and how much of...MORE its size will be taken up by borders and/or sashing. Make a rough sketch on paper or use computer software to draw the quilt.

    Choose a Block Size

    What quilt block size will you use? How many blocks will it take across and down to fill the space within the quilt? For instance, for a quilt that measures about 60" x 80", six 10" blocks across and eight 10" blocks down will fill the space -- 6 X 8 = 48 blocks.

    Be sure to add fabric for borders if you plan to use them, and decide if borders will be cut along the fabric's straight grain or crosswise grain.

    Will blocks be straight set or placed on-point? Multiply the block's finished size by 1.41 to determine the width an on-point block will occupy in the quilt. Take a look at an on point quilt pattern if the term is new to you.

    Will you use plain setting triangles for on-point quilts? You can piece partial blocks to use as setting components, but if you don't you'll need two types of triangles to fill in the jagged edges. Triangles look the same but are cut differently. Be sure to read Setting Triangle Basics for cutting instructions.

    Decimal to Fraction Conversions

    A conversion chart is handy for yardage calculations.

    • .0625 = 1/16
    • .125 = 1/8
    • .1875 = 3/16
    • .25 = 1/4
    • .3125 = 5/16
    • .333 = 1/3 yard
    • .375 = 3/8
    • .4375 = 7/16
    • .5 = 1/2
    • .5625 = 9/16
    • .625 = 5/8
    • .666 = 2/3
    • .6875 = 11/16
    • .75 = 3/4
    • .8125 = 13/16
    • .875 = 7/8

    • .9375 = 15/16

    Continue to 2 of 3 below.
  • 02 of 03

    Analyze Quilt Blocks for Yardage Needs

    how to calculate quilt yardage
    Sample yardage calculations for Birds in the Air Quilt Block. © Janet Wickell

    Sample Yardage Calculations

    Let's pretend we want to make 20 identical Birds in the Air quilt blocks like the one shown in the upper right corner of the illustration. The blocks finish at 9" square.

    Look at the block's grid. It's a nine-patch design, with three major grids across and three down -- nine units in all, even though the lower right block half is made from just one triangle. How to Analyze Patchwork ​offers details about quilt block structure.

    Keep in mind that the instructions below...MORE walk you through the layout of this particular quilt block -- your blocks will differ. Sketch it out as you read, or print the image and follow along with the instructions.

    1. Divide the finished size of the block, 9", by the number of rows across or down, 3. The answer, 3", is the finished size of each of the nine grids.
    2. All nine grids in this block contain half-square triangles, and we must add 7/8" to the finished size of a half-square triangle to calculate its cut size. How to Cut Patchwork Shapes explains how much you should allow for specific seam allowances.
    3. Each block has three dark blue 3-7/8" half-square triangles: we're making 20 blocks, so multiply that by 3 per block = 60 triangles. We can cut two triangles by dividing a 3-7/8" square once diagonally as shown.
    4. 60 triangles divided by the two each square yields = 30 squares required.
    5. Most quilting fabric has a usable width of about 40", often a bit more. Divide 40" by 3-7/8", the size of your squares. The answer, 10.32, is the number of 3-7/8" cuts you can make across the width of the fabric. Slide that back to a whole number, 10 cuts. (See How to Rotary Cut Fabric Strips)
    6. Now divide 30 (the required number of squares) by 10 (the cuts you'll make per strip) = 3 strips required to cut the squares (assuming no waste).
    7. We're almost finished. Multiply 3 strips x 3-7/8" (the width of each strip) = 11-5/8" (total length of fabric required to cut 3 strips).
    8. A yard of fabric is 36" long, so divide the length of fabric required, 11-5/8", by 36". The answer is .32 yard (refer to the decimal conversions on page 1 if necessary). Bump up the yardage to compensate for errors or shrinkage during pre-wash. I would buy 1/2 yard.
    Continue to 3 of 3 below.
  • 03 of 03

    Figure Yardage Requirements for Another Fabric

    how to calculate quilt yardage
    Sample yardage calculations for Birds in the Air Quilt Block. © Janet Wickell

    Now let's figure the yardage requirement for the large green triangles. We'll go through the steps a bit more quickly.

    Each large triangle is three grids high and three grids wide -- 3" x 3 = 9" finished size. Add 7/8" to the finished size for seam allowances, for a cut size of 9-7/8".

    1. 20 blocks x 1 triangle per block = 20 triangles
    2. 20 triangles divided by 2 (the number that can be cut from a 9-7/8" square) = 10 squares required
    3. 40" width of fabric divided by 9-7/8" = 4.05,...MORE or 4 squares per strip
    4. 10 squares required divided by 4 per strip = 2.5, or 2 strips plus about a half strip, each 9-7/8" wide.
    5. 9-7/8" x the 3 required cuts (even though one need be a partial width) = about 30" of fabric.
    6. 30" divided by 36" (one yard) = .83 yard, bump up to 1 yard to allow for shrinkage and provide a bit of excess for squaring up.

    Follow the same procedure for each part of the block, adding together yardages for like fabrics.

    Quilt Border Yardages

    Borders help you easily adjust the size of your quilt top. Vary the number of borders you sew to the quilt or adjust their widths to suit you. Once you've determined widths and styles it's easy to calculate border yardage.

    Read About Quilt Borders before you calculate yardage, and keep in mind that mitered borders require longer strips than butted borders.

    Sashing Yardage

    Calculate yardage for sashing and cornerstones as you would for any other unit in the quilt. Make a rough sketch of the quilt layout to help you visualize how many strips are required.

    More Yardage Helpers