Yarn Calculator
It's a lovely moment when a plan for a new project comes together: the pattern is picked, the colour is chosen, and you have the yarn in your basket. The last thing you want to happen later on is to be three quarters of the way down a sleeve and realise you're a ball short.
Our yarn calculator works out exactly how many balls to buy for your pattern, adds a little extra for your gauge and peace of mind, and shows you how much you're likely to have left over. Just pop in two numbers and it does the rest for you.
How do I use the yarn calculator?
You'll need two numbers, and both are easy to find once you know where to look.
Yarn your pattern needs. Look at the materials section of your pattern, which is usually near the start. Most patterns list a total length for each size, so make sure you pick the figure for the size you want to make.
Length per ball. This is printed on the ball band, the paper label wrapped around the yarn, and it's on every product page in our shop too.
Swatch and safety margin. We've set this to 10%, which suits most projects. Turn it up if you're adjusting the pattern, and down if you're confident in your tension.
Good to know: You can switch between metres and yards at the top of the calculator. Many patterns, especially American ones, give yardage, and the calculator converts the numbers you've already typed so you don't have to.
Why add extra yarn to what the pattern says?
A pattern's recommended yarn amount is based on the designer's own knitting or crochet, at their tension. If your stitches are a touch looser, or you add an inch to the body, you'll use more. Your gauge swatch uses yarn too, and it's worth knitting one properly.
Having a little extra means you're not left hunting for one more ball in the same colour and dye lot weeks later. It's a lot less stressful than playing yarn chicken on the last few rows.
Why does it matter if I buy all my yarn at once?
Yarn is dyed in batches called dye lots. Two balls of yarn that are the same colour but different dye lots can differ just enough to show as a stripe in your finished piece. Buying everything for a project together keeps it all from the same lot.
Request a dye lot when you order
Need to match yarn you already have? You can request a specific dye lot on the product page, and we'll send you that if we have it in stock. You'll find the dye lot number on your ball band, and our guide on how to read a yarn label shows you where.
What if I have yarn left over?
The calculator shows how much of your final ball you're likely to have spare. Leftovers are perfect for smaller projects like hats and mittens, can be used for stripes and colourwork, or you can even use them all together in a scrappy project. There are lots of ways to make sure they don't go to waste.
Good to know: If you finish with a whole ball that you haven't touched, you can send it back through Return to The Nest in exchange for store credit. So buying an extra ball for safety doesn't actually have to cost you anything!
Frequently asked questions
My pattern gives a number of balls, not a length. What do I enter?
Have a look online at the ball of yarn the pattern recommends, and find out the metreage. Multiply the metreage of one ball, by the number of balls the pattern says you will need. For example, 8 balls of a yarn with 100m per ball is 800m. Enter that into the calculator in 'Yarn that your pattern needs', and then enter the metreage per ball of the yarn you're buying.
Can I use the calculator if I'm swapping to a different yarn?
Yes, and that's when it's most useful. Because it works from total length rather than weight, it accounts for the new yarn having more or fewer metres per ball. Do check the new yarn is the same weight or thickness, such as DK or aran, and be sure to knit a gauge to make sure the yarn meets what the pattern suggests.
How much extra yarn should I buy?
For most projects, 10% is plenty. If you're making the garment longer, knitting at a looser tension than the pattern, or working a yarn-hungry stitch like cables, go up to 15% or 20%.
Does it work for crochet as well as knitting?
It does. Crochet often uses more yarn than knitting, but your crochet pattern's yarn amount already allows for that, so you can enter it just as it's written.
Buy once, make happily
Getting your yarn amount right at the start means one order, one dye lot and no last-minute hunting. It also means you can settle in and enjoy the process knowing you are all set.
Bookmark this page for your next project. It works for everything from a pair of socks to a throw for the sofa.
Still not sure how much you need?
Send us a message with your pattern name and the yarn you're thinking of, and we'll help you work it out. We love to talk about yarn!