I have been thinking about starting a new crochet project and it struck me that there were no measurements or calculators online that could give you an estimate of the amount of yarn you would need based on the measurements of the projects result, with fixed terms such as the weight of the yarn, the hook used, and which fundamental stitch was used to create the final result. The goal is to answer this question,

“If I wish to make a square of fabric that is 34 inches by 34 inches, made of half-double crochet using a 5mm hook and worsted weight yarn, how much yarn would I need to complete the project?”

So I decided to find out the answer manually. I worked several styles, including:

• Foundation Chain
• FSC
• FHDC
• FDC
• SC
• HDC
• DC
• SC Strip
• HDC Strip
• DC Strip
  

Where the strips were just a single row of that kind of stitch, and the non-strip measures were measuring the yarn after creating a complete work in the square based on the index, which for all of this was five inches. So, a SC Strip is 5 inches long, one row of SC, and SC is 5 inches wide by 5 inches high.

Here are the numbers that I measured, these are inches of yarn consumed for each category (YCR – Yarn Consumption Rate):

Stitch	Five Inches Length	Average YCR per Inch
Foundation Chain	25.5	4.8
FSC	80	16
FHDC	87	17.22
FDC	82	15.5
SC	785.5	31.42 (per sq inch)
HDC	802	32.08 (per sq inch)
DC	790	31.6 (per sq inch)
SC Strip	53	10.6
HDC Strip	78.5	15.7
DC Strip	102	20.4

What surprised me was that Double Crochet uses less yarn, a little bit, than Half-Double Crochet does, and then just how close the three fundamental stitches are to each other when you hold width and height at a fixed value.

So my answer is, for a 34” by 34” square of fabric, Half Double Crochet with a Foundation Half Double Crochet will require:

FHDC = 34” x 17.22 = 585.48 inches of yarn

HDC = 34” x 34” = 1156 square inches x 32.08 = 37,084.48 inches of yarn

Full Project = 585.48 + 37,084.48 = 37,669.96 inches of yarn, with 36 inches per yard results in 1,046.38 yards of yarn.

So with this information, I know what my project would potentially cost me, outside of the project time itself, so if I select a superwash merino yarn, for example on yarn.com, their Valley Yarns Valley Superwash is $6.49 a ball, and a ball has 97 yards of yarn in it. That requires 10.78 balls, well, really 11 balls. That’s $71.39, with their 20% off deal, their out the door is $64.10.

The really nice part of knowing the rough yarn consumption rate for these stitches is that you don’t have to overbuy your yarn and then end up with extra of anything. There will almost always be partials but there is a big difference between having a third of a ball left versus having 3 1/3 balls left.

If you find these values to be useful, I would only ask that you leave a comment here letting me know that they helped.