Hands up if you’ve ever lost at yarn chicken? *Shoots both hands up in the air and waves them around vigerously*

Whether you’re adapting an existing pattern, winging a project as you go, or taking your first steps in crochet design, it can be tricky to guess how much yarn you will need. So in this post I’m going to share some of the ways in which you can make a reliable estimate.

If you’re working from a pattern, then it really should give you a decent guide as to how much yarn you’re going to need, whether they round it to the nearest ball or give a guidance in total meters or yards, it should be there somewhere!

If you have no guide, or aren’t using a pattern, then follow the steps below to make a decent estimate of how much you’ll need. There’s more than one way to make this calculation so I have outlined two common and approaches; using area or using stitch count.

Create a sample

Regardless of what method you use to make the calculation, you are going to need a sample piece worked in the same yarn and stitch pattern you’re using. This will act as a base measure for your sums.

This could be a gauge swatch or it could be that you’ve started making a project and you want to know how much you’ll need to finish it.

Ideally it will be a simple square or rectangle. Another reason I love swatching!!

The first piece of information you’re going to need to know is how much yarn you have used in this sample (see steps 1-3 below). This will allow you to create a single unit number you can use to size up to make your estimate for the whole project.

Depending on the method you use, thIs unit will either either be the number of meters needed to work a specific area (1cm squared in this case), or the number of stitches you get out of one metre of yarn.

I will look at these methods separately to avoid any confusion!

Note that I work in grams, metres and centimetres but the sums will work with any units of measure. Just make sure you’re consistent!

If you look at this and think *MATHS* and panic, please don’t, just follow each step through (don’t rush ahead!) and you will get there!

Using area to calculate your yarn amount

The steps are given below, followed by a worked example

1. Take your sample and weigh it – write down the weight
2. Use the information on your ball band to calculate how many meters per gram you get from your yarn (meters per ball divided by ball weight)
3. Use your m/g calculation to work out how many metres you have used in your swatch (m/g measurement times weight of swatch)
4. Calculate the area of your swatch (measure the length and width and multiply those numbers together)
5. Work out the number of metres per cm squared your stitch pattern uses (divide the number of metres used by the area of your sample) Write it down!
6. Calculate the area of your final project (this can be a guesstimate for awkward shapes)
7. Work out how many meters you’ll need for the size of your finished project (multiply the area of the total project by your metres per cm square calculation from No. 5)
8. Work out how many balls that is (divide the total meterage by the number of meters in each ball (from the ball band) and round up)

Shall we look at a worked example?

Let’s say we have a swatch of half double crochet 30 sts wide by 24 rows long, measuring 15cm by 15cm, it uses double knit yarn which comes in 100g balls. Each ball has approximately 250m of yarn. (I’m sorry if this feels a bit like a maths test!).

We want to make a scarf that measures 150cm long and 25cm wide.

1. You weigh your sample

It weighs 20g

2. Work out how many metres per gram you get from your yarn

To do this, you divide the total meters in each ball by the number of grams:

250m / 100g = 2.5m/g

So 1 gram of yarn measures 2.5metres

3. Work out how many meters you used in your swatch

You have 20g in your swatch, so:

20 * 2.5 = 50m of yarn in your swatch

4. Work out the area of your swatch.

Your swatch measures 15cm long and wide:

15 * 15 = 225cm squared (note we are working in cm here)

5. Work out how many meters you need per cm squared of area

Divide the total metres used by the number of cm squared in your swatch:

50 / 225 = 0.22222

Write this number down, you’ll need it in a minute!

6. Work out the size of your finished project

If it’s a garment, you may need to work out the size of each panel, or use the body measurements to make an estimate. Likewise if it’s a hat or something similar, you will need to make some judgement calls (if you know the design, you may prefer to use the stitch count method below!)

In our example, we are making a scarf which is 25cm wide by 150cm long, so we can work out the total area of the finished item:

150 * 25 = 3750cm squared

7. Work out the total number of metres needed for your project

To do this, we will multiply the total number of cm squared by the number of metres for every 1cm squared (the number we calculated in step 5)

3750 * 0.2222 = 833.33m

So you now know you will need a total of 834m for your scarf

8. How many balls of yarn is that?

You know that each ball of yarn has 250m so you’re going to divide the total number of metres by the number in each ball

662 / 250 = 3.34 balls

You’ll need to round that up to the the nearest whole number (always round up!).

So if you’re yarn shopping you’ll need to buy 4 balls for this scarf!

Using stitch count to calculate how much yarn you need

This uses a very similar method to using area but instead of calculating your cm square, you calculate stitch count.

Again I have outlined the steps and followed up using the same worked example (lets see if I get the same result!). Steps 1-3 are the same!

1. Take your sample and weigh it – write down the weight
2. Use the information on your ball band to calculate how many meters per gram you get from your yarn (meters per ball divided by ball weight)
3. Use your m/g calculation to work out how many metres you have used in your swatch (m/g measurement times weight of swatch)
4. Calculate the number of stitches in your swatch (number of rows multiplied by the number of sts in each row)
5. Work out the number stitches your stitch pattern uses per metre (divide the number of stitches used by the number of metres in your sample) Write it down!
6. Calculate the total number of stitches you’ll need in your final project (this can be a guesstimate for awkward shapes)
7. Work out how many meters you’ll need for the size of your finished project (total number of stitches divided by stitches per metre)
8. Work out how many balls that is (divide the total meterage by the number of meters in each ball (from the ball band) and round up)

Lets look at that as a worked example

We’ll use the same example with swatch of half double crochet 30 sts wide by 24 rows long, measuring 15cm by 15cm, it uses double knit yarn which comes in 100g balls, each ball has approximately 250m of yarn.

This swatch would have a gauge measurement of 20 sts and 16 rows in 10cm. You could use this to work out that a 150cm by 25cm scarf would need 240 rows and 50 sts in each row (that will come in handy later).

You can read this post to learn how to use gauge to calculate your stitch and row counts. I’ve done it for you in this example because I want to stay on track!

1-3. How many metres did you use in your sample?

From the previous example, we know your sample used up 50m of yarn

4. Work out the number of stitches used in your sample

Your sample has 24 rows with 30 sts in each row:

24 * 30 = 720 sts

5. Calculate how many stitches per metre your stitch pattern uses

You’ll divide the total number of sts by the total number of metres in your sample to find this out:

720 / 50 = 14.4 sts per metre

Note that it doesn’t matter if your stitch pattern uses different types of stitches. So long as your swatch is a representative example of the pattern, this is an average of all the sts.

6. Calculate how many stitches your final project will need

Your final project will need 240 rows, each with 50 sts:

240 * 50 = 12,000 sts (this is a big scarf!)

7. Work out the total number of metres needed for your project

So here we will take the total number of sts and divide it by the number of sts per metre to get the total number of metres:

12,000 / 14.4 = 833.33m

So you now know you will need 834m in total for your scarf – that’s exactly the same number we got when using area!!! (I love it when a plan comes together!)

8. How many balls of yarn is this?

You know that each ball of yarn has 250m so you’re going to divide the total number of metres by the number in each ball

834 / 240 = 3.34 balls

You’ll still need 4 balls of yarn!

So there we have two ways of working out how much yarn you’ll need!

One thing to mention is about using different colours. These calculations are for a single project. If you’re going to be working with different colours, you can use the same steps to break it down to work out how much of each colour you’d need,

Remember, if you’re new to making these calculations so just work through your chosen method step by step.

I used the stitch count method to calculate yarn amounts for different sizes when I’m working on a sweater pattern for example and it’s served me well so far!!

Happy weighing, measuring and calculating!

Dx