Calculating Quilt Fabric Yardage 101

A quilter, Lorraine G., recently asked for quilt fabric yardage requirements for a quilt she planned to make.

Specifically she wanted to know:

With only three unique patches (and all of the same size) to consider, this question provides the perfect example for learning to calculate yardage requirements.

There are two ways to do it.

In the first section we'll explore using quilt design software (EQ7) to figure it out.

Further down this page, we'll use paper, pencil and a calculator starting with a list of the orderly steps in the calculations and then going through our Rail Fence example with two different block design.  

Let's get started!

Using design software for fabric yardage calculations

Due to its limited fabric palette, strip piecing is the most efficient way to piece this quilt.

Using this technique means each strip's width must be easy to cut with a rotary cutter and ruler—that means no 1/3" units since the majority of rotary rulers are labelled in 1/4" and 1/8" increments.

The only ruler I've ever seen with 1/3" increments is the Wonder Ruler, click here to learn about it.

To meet Lorraine's requirements and this cutting limitation, I drafted two different blocks into my Electric Quilt—a quilt design software for both the PC and Mac.

For the patchwork design above, the program returned these yardages:

• Dark: 3-5/8 yds

• Medium: 3-5/8 yds

• Light: 3-5/8 yds

You will need additional fabric for binding. At this time (Nov. '20) these calculations are not available within the EQ program.

On this site, there are charts to help you determine the amount of binding you'll need based on the size of your quilt. Click here for that information.

Swap the position and yardage for just the light and dark fabrics and the patchwork design morphs into this...

The choice is yours!

In drafting this design, it becomes quite apparent that there MUST be a distinct difference in the values of the light, medium and dark fabrics.

Otherwise the design gets really smushy and almost disappears. (Click here to see what I mean!)

What if you don't have the EQ software?

Never fear!

There's ALWAYS more than one way to get things done in quilting.

The trick is finding what works best for YOU and what best fits your budget.

To compute the needed quilt fabric yardage, you'll need paper, pencil and a calculator (if you don't care to do the math in your head).

You'll need to have a quilt design with all of its unique patches identified and sized.

Let's get started!

How many of the unique light patch are needed?

Simply count how many times the light patch appears in the block. In the diagram above it's 4 times.

Multiply this by the number of blocks that contain it:

4/block x 64 = 256 light patches

How many light patches can be cut from a width of fabric?

Each light patch is 2-1/2" x 6-1/2" where 6-1/2" is the unfinished length of a unit. The computation is:

40" strip ÷ 6.5" = 6.153

The decimals go on and on, but there's no need to go further than 3 places.

Since we can't piece with partial patches, round down to get 6 unique light patches from one strip

How many strips are needed?

Simply do the math.

256 patches ÷ 6 patches/strip = 42.666 strips

This time round up because we use full strips, so it takes a total of 43 strips to cut 256 light rectangles.

How much fabric is needed without insurance?

Remember our strips are cut 2-1/2" wide. Determine the number of inches needed by multiplying:

43 strips x 2.5" = 107.5 inches

To convert to yardage divide by 36":

107.5" ÷ 36" = 2.986 yards

Round up to a number your local quilt store will be happy to cut or 3 yards.

Determine your 'insurance'

Insurance will differ from quilter-to-quilter and patch-to-patch.

EQ calculated 3-5/8 yards of a light is needed. The program added an additional 5/8 yds or 22-1/2" extra.

Only you can decide if that is right for you. Some of the things that whittle away at the extra inches include:

• Fabric shrinkage if you prewash (it tends to shrink more on the crosswise grain and you may not get as many patches from each strip after washing)

• Squaring up after several of cuts

• Fewer patches can be cut from strips cut crooked at the fold

• Miscuts

• Using a fabric cutting machine like an Accuquilt
  

For this quilt, 5/8 yard looks like a fair amount. Any leftovers can be used in a scrap quilt later, or perhaps even in a pieced backing for THIS quilt.

Since each unique patch is identical in size, the quilt fabric yardage for the medium and dark fabrics is also equal to 3 yards PLUS your insurance amount.

A note about 'usable width' and strip piecing...

The strip piecing technique adds an extra 'twist' on the quilt fabric yardage calculations.

If all the rectangles are cut and stitched individually, then it doesn't make any difference if the yardage is of different widths—simply do the computations for each unique patch from each unique fabric.

With strip piecing, the fabric-strips are sewn together, pressed and then cut into units/patches. If there are several different usable widths, then use the narrowest measurement for the calculations for each fabric used in the strip set.

You can easily see how a narrower width could possibly effect the number of patches able to be cut from each set.

My best advice

Write everything down. Date it, too.

That way you have a record if you have to come back at a later time.

It's faster to check your work, than recalculate everything.

Take it one step at a time.

You've got this!