Another question I see often is How much yarn do I need to complete a blanket of a certain size? Or… I have 2 balls of yarn and will it be enough to make a scarf? But mainly what triggered this topic is the question I asked myself after not writing down the amount of yarn I used when writing a pattern: How much did I use?? Discovered this past week that I did that with 3 patterns I am working on. THREE!! Sigh… So in the interest of helping myself, I will try to help you calculate yardage needed. Or used…
Before we start, here is the cheat sheet to what is written in the equations.
- When you see a lower case x in the equation, it means to multiply.
- When you see a forward slash /, it means to divide.
- Grab a calculator and solve!
If you use the metric system, all you need to do is just replace yards with meters, and you are good to go!
How do I calculate how much yarn BEFORE I start a project?
In order to calculate the yardage needed before you start, you will need to work a swatch. Before starting the swatch, measure 5 yards of yarn or use a little device that measures yarn as you go and cut. If you don’t want to cut it, place a pin or something else at the 5 yard spot. You will then work your swatch with the stitch you are going to use in your project until you have used all of the 5 yards. Count your stitches. You can calculate the total by counting how many worked across and multiply that by how many rows you worked. The equation will look like this:
(number of stitches) x (number of rows) = total number of stitches
Now you know how many stitches you worked with 5 yards of yarn. Now you divide that by 5 to get how many stitches are in a yard.
(total number of stitches in 5 yard) / 5 yards = number of stitches in 1 yard of yarn
You can work the swatch with just 1 yard. It will be tiny though. Remember that you will also need to measure for gauge as well.
Now you measure how wide and tall it is just like you do when measuring gauge. When you know how many stitches are in an inch, you can calculate the total number of stitches needed to create the size you want. Which will also give you the number of pegs to cast on when you do start your project.
First, you will multiply the number of stitches in an inch by the total inches for the width.
(number of stitches in an inch) x (total number of inches wide) = total number of stitches across
Second, you will multiply the number of rows by the total inches in the length desired.
(number of rows in an inch) x (total number of inches long) = total number of rows long
Third, multiply the 2 previous answers together to get the total number of stitches in your finished item.
(total number of stitches wide) x (total number of rows) = total number of stitches in the project
You will now divide the total number of stitches by the number of stitches in a yard to get how many yards you will need to work this item.
(total number of stitches) / (number of stitches per yard) = total yards of yarn
If you need help with gauge in general, you can reference my previous article on gauge by clicking here.
How do I calculate how much yarn I used AFTER I completed a project?
If you have the item on hand, you will just need to weight the item and do some simple calculations.
I use a postal scale to weight my items. You can also use a food scale or other scales that weight small amounts.
First you need to know how much your yarn weights per yard. The amount is usually so small that you cannot just weight a yard of yarn. You will either need to weight 5 yards and then divide by 5 or you can just get a rough calculation from the skein of yarn itself.
If you still have the band or label from the yarn, there are 2 key pieces of information that will help you in this. The weight of the skein or ball and the yardage in that skein or ball. All you will do is this:
(Weight in grams or ounces) / (amount in yards) = how much a yard weighs in grams or ounces
Now that you know how much a yard of the yarn you used weighs, you then weight your completed item and divide the total weight of the item by how much a yard of the yarn weighs. Which is this:
(Weight of item) / (weight of a yard of yarn) = how many yards you used
If you don’t have the item but needing the yardage because you are writing a pattern and forgot to write it down before shipping it off because your name is Renita and you are forgetful, you will need to use the same method as calculating before starting a project.
Or you can just calculate how much yarn you have left over using the method of weighing the yarn left over and subtract it from the total number of yard in the skein. If you used more than one skein or ball, just add the total used before the partial skein by adding the total yards in each skein based off of the yards listed on the label then add the yards used in the partial skein to get the total yards.
Well that was deep and about as clear as mud. If we are lucky, all the math has been covered now. Maybe…
Questions lead to answers which is knowledge. Knowledge is power. So be powerful! Keep asking questions and keep on loom knitting!