How to calculate yarn yardage
Calculating the amount of yarn I need for a project took me some time to wrap my head around mostly because I like to avoid math at all costs and I also don’t like to make swatches but after loosing one too many games of yarn chicken I decided that I need to figure it out.
I must admit that although it may be tedious it is not hard and once you figure it out, things become much simpler.
To calculate your yardage you will need a few things in addition to your swatch. You’ll need a tape measure, kitchen scale, calculator, the yarn label for the yarn you’re using, a pen/pencil and notebook/paper.
Step 1 - Measure your swatch
Lay your swatch flat and measure the length and the width and write down both numbers.
Next multiply the length by the width and write down the answer. My swatch length is 6.5” and the width 7”.
6.5 x 7 = 45.5”
Step 2 - Weigh your swatch
Turn on your scale and be sure to zero out any previous numbers and set it to measure in grams (I find grams gives the most accurate results)
Place your swatch on the scale and write down the weight.
Now we know that our swatch weighs 24.4 grams.
Step 3 - Calculate the total inches of your project
The figure the total measurement of your project, you have to multiply the total length by the total width. I will be using the measurements of my Divine Scarf Pattern as an example but I will also provide notes on how to calculate measurements for a cardigan.
The measurements of my Divine Scarf is 83.5” long and 12” wide. To get the total inches we have to multiply
83.5 x 12 = 1002”
If you are working on a cardigan you will have to multiply the length and width of each piece of garment and then add those number together.
Step 4 - Calculate how many times your swatch fits into your finished project
To do this we need to divide the total measurement of our project by the total measurement of our swatch.
The total measurement of my scarf is 1002” and the total measurement of my swatch is 45.5.
1002 / 45.5 = 22.02 times (I will round down and use 22 from this point on)
Now that we know how many times our swatch fits into our project we can figure out how many grams and yards of yarn we will need to complete our project.
Step 5 - How many grams of yarn is needed to complete our project
To do this we need to multiply the amount of times the swatch fits into our project, which is 21.25 by the weight of the swatch, which is 24.4 grams
22 x 24.4 = 536.8 grams of yarn need for our project.
With this information you can look at your yarn label and buy the amount of skeins/balls/hanks needed for your project.
Looking at the label for the yarn I chose to use for my scarf, I see that it comes in 100g skeins. In order to get 536.8 grams I would need to buy 6 skeins of yarn.
I am now going to take this information a little further and show you how to figure out the total yards per gram of your yarn and how to figure out the total yards of yarn needed for your project.
Step 6 - How to Calculate yards per gram
To figure this out we would use the information provided on the yarn label and divide the total yards (my yarn is 208 yards) by the total grams (my yarn is 100 grams).
208 / 100 = 2.08 yards per gram.
What this means is that for every 1 gram you get 2.08 yards of yarn.
Step 7 - How to calculate how many yards of yarn is needed to complete your project
To figure this out we multiply the total weight of our finished project (we did this in step 5) by the yards per gram of our yarn.
When we calculated our project weight in step 5 we got 536.8 grams and we now know that we get 2.08 yards per gram for the yarns used for this scarf.
536.8 x 2.08 = 1116.5 yards of yarn needed to complete project.
Now if we divide the total yards needed for our project by the total yards in each skein of yarn you will get the number of skeins needed for the project.
1116.5 / 208 = 5.36 skeins of yarn needed for our project so we would buy 6 skeins.
Something to note
When working with project that you will add fringe or a decorative border to buy extra yarn because when we make our swatch we don’t normally add the finishing touches that will be used to the swatch (you can make a swatch using your border stitch and repeat the calculation process). These calculations are only accounting for the main parts of the project so always keep in mind how your project will be finished so you can always ensure you have enough yarn to finish your project.