How to Work Out Fabric Requirements for English Paper Piecing

I've always been a cut-first-think-later kind of girl. I usually dive into a new quilt without a second thought for whether I'll have enough, and this enthusiasm usually holds me in good stead because most of my quilts are scrappy, and I'm happy to find a work around if I run out of something.  

But recently I was asked to make a quilt out of these beautiful Harmony Fabrics, by Carolyn Gavin for Conservatory Craft and Free Spirit (in stores September '23). I wanted to make sure I had enough fabric to make scrappy diamonds and corner triangles before I started cutting because I couldn't easily get more, and I'd agreed to only use the collection in the quilt. The added bonus of working out the fabric requirements before cutting, was that I could cut everything I needed before starting the quilt, and avoid over cutting and having shapes of this beautiful fabric I might not use in a different quilt. I might have just converted myself!  

Today I want to share with you how I work out fabric requirements in 2 different scenarios. The first is if you're using a fat quarter bundle and you want to know 1) if you'll have enough fabric, and 2) how much of each fabric to cut if you want an even spread.  

The second scenario you might find yourself in is if you want to use the one fabric for a background or repeated shape, and you want to know how much to buy (or if you have enough in stash). 

***Note! I cut almost all my EPP from strips of fabric, and I work out all my yardage this way. If you're fussy cutting this method doesn't apply.

1. Check the direction of your fat quarter. A fat quarter (FQ) is a popular way of cutting fabric that gives you a small, usable piece for patchwork. It is cut from a half yard of quilting fabric down the centre fold, with the selvedge at each end. The FQ generally measures 18" along the selvedge by 22" along the width. In my patterns, I call this width a WOFQ, or Width of Fat Quarter. It's really important with these calculations that you cut your fabric in the same direction as the diagram above. That way, you will always be able to use the same numbers for working out your fabric requirements. 

2. Work out the size of the fabric strip. First, place your shape on your quilting ruler, or on the fabric, laying the quilting ruler over it. Then add an extra 3/8" to each side of the shape to give your strip size. For this 8pt diamond below, it's 2 1/4". (Actually, it's a little less, but I don't want to spend a lot of time lining up the exact number, so I've rounded it to the closest 1/4".) Cut your strip along the WOFQ.

3. Work out how many shapes fit on the strip. Cut the shapes along the strip, allowing an approximate 3/8" seam allowance on each side of the shape. Sometimes your shape will nestle neatly beside your last cut, sometimes you'll need to flip the shape over, and sometimes, like with hexagons, it's fine just to cut a square or rectangle.  After cutting my 8 pt diamonds from the strip, I had 6 diamonds. Write the number down so you can remember it in a bit. 

4. Work out how many shapes fit on a fat quarter.  Remember, you're cutting strips along the 18" length. Divide 18 by the size of the strip (2 1/4). I should get exactly 8 strips from a fat quarter, with 6 on each strip, giving me 48 shapes cut from a fat quarter.  

5. Work out how many fat quarters you need.  My pattern calls for 576 diamonds, so I'll need 12 fat quarters (just for the diamonds). In this collection, I had 15, so I now know that I have enough. But I don't want to just cut 48 from the first 12, and have 3 left over. I want an even spread from each print. That means I want to work out how many strips I cut from each fat quarter. 

6. Work out how many WOFQ strips to cut.  576 diamonds divided by 15 prints equals 38.4. So I want to baste 38 or 39 shapes per print. (If you're mathy, you could get more exact than this, but I'm not. And I don't mind have a few leftover so I ave more choices for fabric mixes as I'm getting to the bottom of my diamond pile.) Divide the number of shapes you need per print (39) by the number of shapes that fit on a strip (6) and you get 6.5. This means you need 6 1/2 strips per print to get an even spread. I cut 7 strips from each print and kept the scraps for the triangles. 

For my next version of Willoughby, I made all the triangles that surround the star a single colour. Here's how to work out yardage if you want to make a quilt this way. 

1. Work out the size of the fabric strip. Place your shape on your quilting ruler, or on the fabric, laying the quilting ruler over it. Then add an extra 3/8" to each side of the shape to give your strip size. For my half square triangle, it's 2 1/4". (Actually, it's a little less, but I don't want to spend a lot of time lining up the exact number, so I've rounded it to the closest 1/4".) Cut your strip from the width of fabric (WOF).  

2. Work out how many shapes fit on the strip. Cut the shapes along the strip, allowing an approximate 3/8" seam allowance on each side of the shape. I can fit 17 half square triangles along a WOF strip.  

3. Work out how many strips you need. I need 576 white triangles. Divide that by 17 = 33.9. You always need to round this number up or you won't have enough. I need 34 strips of fabric.  

4. Work out the yardage. 34 strips at 2 1/4" each strips is 76.5". Divide by the length of a yard (36"). My calculator tells me I need 2.125 yards of fabric. This is 2 yards plus 4 1/2 inches. I always recommend rounding up when either buying or checking your stash, because you don't know if you're going to get distracted and accidentally cut a 2" strip that you can't use. I would want at least 2 1/4  or 2 1/3 yards of white.