Math Monday: Calculating Yards per Gram

Last week I wrote about the mystery yarn I picked up from Harrisville Designs at Rhinebeck - the one without a name or a label to list yardage or weight.

Maybe you have some yarn in your stash that doesn’t have a label or a partial skein that you knitted long ago, but you have no idea what it is. This week, I’m going to show you how to use simple measuring and math to calculate how much yardage is in my mystery yarn. You can try it with your stash mysteries too!

You’ll need 3 things: a rigid ruler, a scale that measures grams and a calculator - your phone calculator will do nicely.

Step 1: Weigh your skein or cake. In this picture, you can see that the cake’s weight is 113 grams.

Step 2: This ruler is 1 foot long. A yard is 3 feet long. I wrapped the yarn (without pulling too tightly) around the ruler 9 times. 9 feet of yarn divided by 3 feet per yard = 3 yards. So I have 3 yards of yarn.

Step 3: Weigh 3 yards of yarn you measured out. You can see that the 3 yards weighs 2 grams.

Step 4: Now the math part. We’ll set up a ratio. Don’t be scared. You did this in 8th grade.

x is the unknown yardage of the cake. We know the cake weighs 113g. So on one side of the equation we write x over 113. We also know that 3 yards of yarn weigh 2g. On the other side of the equation we write 3 over 2. When you do this, be sure that your yardage is on top and your weights are on the bottom on both sides of the equation.

Now cross multiply: x multiplied by 2 on one side of the equation (2x) and 113 multiplied by 3 (339) on the other side of the equation.

Now solve for x. You might remember that what you do to one side of the equation, you must do to the other side of the equation. So divide both sides by 2: 2x divided by 2 equals x; 339 divided by 2 equals 169.5.

And there you have it. You’ve calculated your yardage!!! This means that 113g of this yarn has 169.5 yards in a cake of 113g.

Of course, each skein varies a little in weight. I can use my calculated yardage per skein as an estimate or, if I want a more accurate accounting of how much yarn I have, I can weigh each skein and calculate more precisely by substituting the weight of each skein for 113g in the example above.

Give it a try and let me know how it goes.

Math Monday: Mystery Yarn - The Adventure Begins

Way back in a far away time that seems eons ago (October 2017) my good friend Lee and I went to Rhinebeck, otherwise known as the NYS Sheep and Wool Festival, and not for the first time. Up to that point, we had gone every year for a good many years. For a bunch of reasons, we haven’t been back since, but once this is all over…

As we trolled through the outside buildings on a warm autumn day we came across the Harrisville Designs’ booth. Besides having their own great yarns, Harrisville also does custom spinning for a number of other well-known brands of yarn. We stopped in our tracks when we saw that they were launching n I g h t s h a d e s and spent awhile admiring it. I bought a sweater’s quantity of their lovely WATERshed. Lee kept looking. And then she called me over to the sale bin.

See our Harrisville bags?

Inside was a rustic two-ply wool that was unlabeled. We asked about it, but the only thing the kind Harrisville lady told us was that it was a mill end and that it was 100% wool. Harrisville spins for Brooklyn Tweed, We were both a little smitten. Lee bought 5 skeins. I bought the remaining 3. Occasionally, Lee or I would talk about the yarn, yet neither of us ever did anything with it.

All 8 skeins nestled together!

Fast forward to January 2021. I was doing my semi-annual stash purge and once again came across this yarn. I was still in love. Now you should know that I never to design with any yarn that is discontinued or that I know will be, and certainly never with homespun or an unknown yarn. But this yarn was calling out to be a textured pullover. My 3 skeins wouldn’t do it. So I called Lee, asked her if we could trade - she gave it to me - and it started. The pullover is done, but not yet released.

Over the next few Mondays, I’m going to be writing in this space about yardage. We’ll be estimating and calculating. Yes, it’s math, but don’t be scared! It’s not trigonometry and it’s really rather simple. How will it help you, the knitter? You can calculate yardage you’ve used or how much you need, or how much you’d need if you change an element in your own knitting - like making short sleeves instead of long, or lengthening the body of a sweater. Or perhaps you have your own mystery yarn and want to know if you have enough? Once we’re through, we’ll figure out how we can estimate yarn weight based on yardage.

Analyze this!