How to determine yarn amounts for an item


I did a blog post on “How do I calculate costing on my crochet items?”, as so many ask me that question.

The other most frequent question I get asked:

“How much yarn will I need for making X,Y,Z?”

And my answer always, just to make the ladies frown is:

“I have noo idea!”


And really, I don’t know!

There are so many things that influence the amount of yarn you will use for an item.

The fibre content, the yarn twist, your tension, and the pattern you use, all this influence the amount of yarn you will need to make your item.

Colours of Grace

How does it all influence the yarn amounts then?

1. Fibre?

Some fibres are heavier than others.

For example, you will use way more cotton or bamboo than merino wool when making the exact same pattern, as cotton and bamboo are your heaviest fibers.

2. The twist?

Higher twist yarns are shorter than lower twist yarns of the same weight.

Example; Locally we have the Elle Premier Cotton brand, which have a high twist and comparing to our local Vinnis Collours Nikkim Cotton, which have a low twist, you will use MORE Elle Premier Cotton than Vinnis Colours Nikkim when making the exact same pattern.  When you read the yarn labels, you will also see that the Elle Premier Cotton is shorter that the Vinnis Colour Nikkim on 50g balls, to confirm this theory.

3. Tension?

Firm tension will use less yarn than loose tension.

4. The Pattern?

Different stitch patterns will use different amounts of yarn.

Example; Solid stitch patterns, firm textured patterns like popcorn stitches, puff stitch, bullion knot, cables, even the granny square, etc, will use more yarn that a lacy pattern or patterns with larger spaces between cluster stitches.  Your way of joining an item, will add to the amount of yarn used.

These are only the basic factors that will influence the amount of yarn used for a specific item.

Can you see how difficult it actually is to thumb suck yarn amounts for projects?

To estimate can put you way of track.  How can you purchase your yarn if I will tell you that you MIGHT need somewhere between 8 and 12 50g balls of yarn to crochet that baby blanket for your niece…(not knowing the EXACT VARIABLES in the pattern, your tension, etc that will influence the yarn amounts).  When you work in a solid colour, you have to consider the lot number, as you will have to buy ALL the yarn at once, to make sure you get the CORRECT amount of yarn for from the same batch.  Especially when you want to use the hand dyed yarns!

Let me give you some guidance in determining your yarn amount, BEFORE you purchase your yarn for your project(s).

What I need:

  1. A digital scale. (Seems like this becomes one of the important crochet tools?)
  2. Measuring tape
  3. Note book
  4. Pencil

Calculate Yarn Needs

I’m very sorry to say, that you will have to do the ONE thing all crocheters hate to do!!

1. Crochet a gauge swatch from the pattern you are going to use!!!

Yes, I know!!  I hate it too!! But if you want to be accurate, you HAVE to do it!!

This swatch will help you to get yourself familiar with your pattern, see where you are having trouble with the pattern, if it is a block blanket you want to make it will give you a better decision on your method of joining as this should be determined BEFORE you start your blanket!

2. Determine the finish measurements of your item.

If it is a blanket you want to make, decide before hand how big you want this blanket to be.  Length x Width

For garment pieces, the safest will be to draft the panels of the garment piece with its finished measurements.  You can do a square with the finished length and the bust or hip circumference so you can have the surface in Length x Width.

3. Measure your swatch.

Length x Width

4. Determine how many of the swatch blocks will cover the surface of your item.

5. Weight your swatch block.

6. Determine the weight of your final product by

The amount of swatch blocks that will cover the surface of the item MULTIPLIED BY the weight of the swatch block.

The answer will be the amount of yarn in weight that you will need to buy to finish your item.


  1. I want to make a granny square blanket for my double bed, so I will crochet a granny square in the size I want it.
  2. The double bed is 190cm(width) x 150cm(length) if I measure the mattress. Adding 20cm over hang on sides and the feet end.

(190cm + 20cm) x (150cm + 20cm + 20cm) = 210cm x 190cm

  1. Swatch measures 15cm x 15cm (using the yarn of my choice, having my average tension, not caring much about the twist of the yarn)
  2. Now I have to calculate, how many 15cm x15cm squares will fill up the surface of 210cm x 190cm.


Making it simple:

The length will be 210cm/15cm = 14 blocks to make up the length of the blanket.

The width will be 190cm/15cm = 12 block but 10cm short to 190cm.  12 block will give me a width of only 180cm.  Now I can decide it I am happy with a 180cm wide blanket, or would I like to add 15cm to make it 195cm rather?  Well, the latter is closest to my original measurement, so I would add another 15cm block to give me a 195cm wide blanket.  So I will use 13 blocks to make up the width of the blanket.

13 blocks for width x 14 blocks for length = 182 blocks that I will need to cover the surface of a 195cm x 210cm blanket.

  1. The 15cm x 15cm swatch block weighs 20g.
  2. 20g x 182 blocks = 3640g of yarn.

To determine the amount of 50g balls for instant: 3640g/50g = 72.8 50g balls (rounded off to 73 balls)


You will see that I did not make provision for the amount of yarn I will use to join the squares.

Granny JoinWhip Stitch

This is a separate calculation when you determined your method of joining.  Remember, some joining techniques will add to the measurements of your blanket, like the granny join, the flat braid, simulated braid or chain joining techniques.

The whipstitch, single crochet, slip stich crochet or crab stitch join, will keep the original finished measurements, as these are joining techniques that do not necessarily add to the measurements of your final item.

Calculating the amount of yarn using to join will expect very similar method of calculation.

Very simplified: Weigh about 4 of your blocks, join them in the method you chose, weigh them again and the difference between the two readings will be the amount of yarn you used to join 4 squares.

I’m sure you will be able to calculate the rest J


I hope this guideline will help you to make more accurate calculations of yarn needs, so you don’t buy too much or too less yarn for your products in the future.

This will also help you on budgeting for that special blanket you wanted to make for a very long time now.  When you know approximate how many grams of yarn you will need, you can determine how much it will cost.

Happy Hooking!







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