How to calculate yardage (in four easy steps!)

Have you ever been in a situation where you have a lovely ball/skein/hank/glob of yarn, and you don’t know how many yards you have? This can also happen if you’ve lost the label and forgotten the brand, or if you have some hand-spun yarn. Luckily, there is a way to calculate yardage with just a couple steps! (Fair warning: it involves a bit of algebra…but if I can do it, so can you!)

Disclaimer: This method worked with my wool yarn – I’m not sure how it will work with other fibers. It’s not intended to give an exact measurement! I’m just sharing what works for me. 🙂

Step 1: Locate the ball of yarn and weigh it. I like using grams because then we don’t need to deal with decimals. Write down your measurements.

Step 2: Grab a ruler and measure the Wraps Per Inch of your yarn. What we’re doing here is determining the weight of your yarn. Here’s a link to ‘Determing Yarn Weights with Wraps Per Inch‘. (Also check out the Ravelry Standard Yarn Weights – the only problem is they don’t do wpi for thinner yarns.) Count how many wraps of yarn you have per inch, then find out what weight it is. This blue yarn has 25 wpi, so it’s a lace weight yarn.

Step 3: Next we need to ‘compare’ our skein to a skein where we know both the weight and the yardage. That’s why we found out the yarn weight. I like to use Joann.com for this, but to make things easier, I’ve written up a table for you! (The table is based on random skeins of the appropriate weight – that’s why the numbers seem so random.)

WordPress won’t let me upload the chart, and it also won’t let me do tabs, so forgive the rather rudimentary chart below!

Yarn Weight……….Grams……….Yardage
Lace…………………100…………..500
Fingering…………….100………….329
Sport………………….50…………..196
Double Knit (DK)…….141………….459
Worsted………………198………….364
Bulky………………….113………….155
Super Bulky………….142………….81

Step 4: Now it’s time to use all these numbers to (finally) calculate the yardage. When I say ‘commercial yarn’, I mean to use the table to find the numbers for your yarn weight (lace weight for me.) If you know basic algebra then you can plow right ahead and ignore my guidance. 🙂

Your Yarn Weight                           Your Yardage (X)
_________________________  =  __________________________
Commercial Yarn’s Weight        Commercial Yarn’s Yardage

Here’s what it looks like for me:

15          X
____ =  _____
100       500

No need to reduce fractions or anything like that. Just multiply diagonally so it will end up like this (using * for the times symbol):

Your Yarn Weight * Commercial Yarn’s Yardage = Commercial Yarn’s Weight * x

Here’s what it looks like for me: 7,500 = 100x

Next, divide both sides by the number next to X (you know the drill) and that number is your yardage.

So I have about 75 yards of lace weight yarn. (Another handy thing about this process is that you find the yarn weight at the same time!)

Phew!

“How accurate is this process?” you ask. Good question, and I was curious myself – in theory it works, but how accurate is in theory? So I applied this process to my first skein of yarn, the one above, and got 24 yards. Then I manually measured it and it was 23 yards. Pretty close, in my case! Still, this isn’t an exact science and it might work differently with different fibers. It does give you an estimate, at least!

Now I’m off to figure out what to make with my handspun yarn!

P.S. I made a new page to keep track of my spinning exploits – you can view it here if you’re interested. 🙂