How to calculate yarn length from weight

We’ve all been there. We’ve got a big pile of yarn (inherited from a family member, the result of frogging a project, or maybe even a thrift store find)… and we have no idea how much yardage there is!

Since most patterns specify the number of yards you’ll need, determining the yardage of your yarn is crucial. Fortunately, it’s not too tricky! In this post, I’ll show you how to use a scale to calculate the yardage of your yarn.

Materials required

To calculate the yardage of your yarn, you’ll need:

  • the yarn (duh!)
  • a digital scale
  • a box or bowl (to hold the yarn on the scale if you’ve got a lot of little bits of yarn)

Step-by-step: How to determine yardage

Got your materials together? Okay, let’s get started!

Find out the yarn’s yardage per weight information

I lucked out a little bit: I had a big bundle of yarn that came along with a label. The label tells you how much length/weight a particular ball of yarn is:

If you aren’t lucky enough to have a label, you have some options:

  • If you know the type of yarn you have, look it up in Ravelry’s yarn database. It’ll tell you the yardage/weight.
  • If it’s mystery yarn, you’ll have to manually measure and weigh a small sample. Boring, but easier than measuring the entire amount of yarn!

Calculate length per unit of weight

Now I know that my yarn has 100 meters in 50 grams. I want to calculate how much length there is to each gram.

So, each gram of yarn is 2 meters long. We’ll keep this in mind!

Weigh your yarn

Since I have a lot of little balls of yarn (the result of frogging a sweater), I’m using a box to keep them all together on the scale. Put the box on the scale, and zero the scale:

It’s important to put the box on the scale before you zero the scale, so that the box won’t be included in the weight. Zeroing the scale just means that you’re telling the scale to start at zero… and it’s easy to do. On my scale, I just hold down the ‘tare’ button. See how it’s now reading ‘0’?

Since my yarn label listed the length/weight in metric, I’m going to weigh my yarn in grams.

Put the yarn that you want to weigh in the box:

And weigh it!

And it weighs…

472 grams. Good to know!

Calculate the yardage

Now all we need to do is calculate our yardage! We know (from before) that each gram is 2 meters long, so we multiply 472 (how many grams we have) by 2 to get our total meters.

To do the final conversion from meters to yards… you don’t even need to do any calculations! Just type ‘convert 944 meters to yards’ into Google, and it’ll give you the answer!

What will you make now?

Now that you can determine the length of some of your mystery yarn, what are you going to do with it? I turned mine into a Kyuu cardigan… I’ll update you on that, later!

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May 29, 2012 | Posted by in Blog, Tutorials | 12 comments

Comments (12 Responses)

  1. Robin says:

    I’m not sure how you figured this out (well I have an idea, and it’s more math than I care to think about!), but I’m so glad you did! Now I’ll be able to tell if I have enough for two socks or just one! Thanks for the great tip!

  2. Truly Myrtle says:

    I have some mystery skeins – I hadn’t thought about measuring and weighing a small amount! Doh! Thanks heaps!!!

  3. Mamayir says:

    This issuch helpful information! Thanks Saceyfor continuing to make crochet (and other such yarn work) fun to do! ^_^

  4. I always have this yardage problem with the local made yarn, since there is no yardage info provide. I did exactly the same way you mentioned about to actually roughly calculate yarn length too and I just happy to know that you recommend this method too.

  5. Barb Jackson says:

    So how do I calculate if don’t have the gram to meter info?

    • Stacey says:

      That’ll be more difficult. I would determine the thickness of the yarn (by calculating wraps per inch), and then determine the fiber (google ‘fiber tests’), and then find a similar yarn. The weight/yardage info of yarns of similar thicknesses and fibers will be very close.

  6. […] for those times when you wonder if you have enough yarn to finish your project.  Stacey over at has put together a great tutorial to show you how to use electronic scales to calculate the […]

  7. GIGal says:

    I have a pattern I want to make for an afghan without instructions. I need to calculate how much length of worsted weight (4) yard I will need using size 10 needles using 2 strand of yarn at a time.
    How do I do that calculation so I buy enough of one dye lot?

    • Stacey says:

      You’ll need to crochet a swatch, and calculate how much yarn is used in the swatch. Then, figure out what proportion the swatch is in relation to your afghan!

  8. […] and calculate from there. If it’s in balls, and you happen to have a ball band, you can weigh the yarn and do a little math. You can also run it on a yarn swift and count how many times around it goes […]

  9. […] Fresh Stitches Yarn by Weight Tutorial When I worked out how much each weighed, and then how much length there was to each ball, I just bagged the yarn in little freezer bags, scribbled a note on the outside and at last know what I have. […]