How to Calculate Raglan Construction?

How to Calculate Raglan Construction?

When knitting a raglan sweater or a cardigan, the question is how to calculate the raglan increases or decreases so that the upper part of the garment fits the body perfectly.

The joining of the raglan shoulders should be a line that is formed by the decreases from the armpit to the shoulder. We need to know how many stitches to increase or decrease in how many centimeters to make that calculation. Generally, 1/3 of the number of stitches of the back piece (or front piece for sweaters) is decreased within the row number obtained by dividing the measurement of the shoulder in centimeters by 2. Once we have the number of stitches to be decreased or increased in a certain number of rows, we make a scheme and start the process.

Raglan Decreases for Sweaters – Down to Up

I knit sweaters with 4 main pieces: Back, front and two arms. Once the point where the decreases begin is reached, all the raglan lines should progress in the same way. We are talking about sweaters here, but this method works for any raglan garment such as cardigans, pullovers or jumpers, too.

  1. Since the back and front pieces have the same width, take 1/3 of that width for women’s sweaters. For men’s sweaters, I prefer to leave more stitches in the middle. Therefore, the middle part should be 1/3 + (5-10) stitches. For example, let’s say we have 90 stitches for the back piece. For a women’s sweater I would divide them as 30-30-30. However, for a men’s sweater I would divide them as 25-40-25.
  2. There are two ways of measuring the length of the decreases. I prefer measuring the arm at the point closest to the shoulder (upper arm), adding 5-6 more centimeters and dividing that number by 2. For example, if the measurement of your upper arm is 50 centimeters, you can take 60 centimeters as a reference (if you want tighter arms, add 3-4 cm, not 10) and note the length as 30 cm.

Another alternative is to vertically measure the length from the point where you stopped to make increases to the horizontal middle of your shoulder (where you want the seaming to be). After that, use your gauge to calculate the number of rows you need to reach that length.

  1. We have the number of stitches we need to decrease and how many rows we need to decrease them for. Since we need to decrease the same number of stitches in the same rows which correspond to each other in back and arm pieces, we need to make the scheme here.
Raglan Construction (Decreases)

Raglan Increases for Sweaters – Up to Down

I generally prefer making sweaters with seams since the seams provide a more intact look and high durability. However, some patterns require knitting up to down; thus, our raglan decreases become raglan increases. For up to down garments, especially if you are newly adjusting to this method, the most important thing to keep in mind that the stitches must increase. This may sound odd; however, for a knitter who is used to working with raglan “decreases”, a careful calculation is essential.

  1. Once you finish with the neck part of the sweater, count your stitches and divide them with the little knitting pins. Remember that, the number of stitches you leave for arms should be the same and, if this is a sweater, the number of stitches for the front and back parts will be the same.
  2. Remember our 3 parts from the decreasing calculations? We will use that again. Now, the number of stitches we left in the middle will be the starting point. We will increase 3 times that number. For example, if we need to have 90 stitches for the back piece, we need to spare 30 stitches for the back piece for women. For men, we need the middle part to be wider; therefore, we spare 40 stitches for the back piece.
  3. Since this is settled, we can place the little pins. For example, let’s say we started with 80 stitches and made the neck as we like. At the first round of raglan increases, we place a marker on the first stitch and assign a piece to that. Let’s say we are starting from the middle back. The 80 stitches will be divided as follows:

Back: 30 stitches

Left Arm: 10 stitches

Front: 30 stitches

Right Arm: 10 stitches

  1. Starting from the marker (the middle of the back) knit on 15 stitches, place a marker, knit 10 stitches, place a marker, knit 30 stitches, place a marker, knit 10 stitches, place a marker, knit the remaining 15 stitches of the back. We have a total of 5 markers.
  2. Now, we can measure the length until the point where we will separate the arms from the body, calculate the number of rows using the gauge and make our scheme.
Raglan construction (increases)

Making the Scheme

The scheme is very important for me when making such calculated and delicate increases and decreases. The stitch counters work well while you are knitting on straight, however; for the increases and decreases, you need your pen and paper to mark each of them. Otherwise our carefully made calculations will not give the result we desire.

For both methods of knitting, we calculated how many rows we need. Firstly, we make a list by writing the numbers from 1 to the desired number of rows. Let’s consider an example that we make increases or decreases in 35 rows.


We have our list now. Let’s add decreases or increases. Let’s say that we need to decrease 50 stitches (25 decreases in each side) in 35 rows. For the raglan line to be smoother, we need to spread the decreases to the rows as evenly as possible. Since we need to make decreases in 25 rows, that will leave us 10 rows which we will knit straight. I will denote the rows where we do not make increases or decreases as S.


Notice that I followed a pattern here. It goes as two rows with decreases and one straight, three rows with decreases and one straight. Try to make patterns such as this one so that the increases or decreases will look smoother. Now, let’s complete the scheme. I will denote the rows with increases as D.


Our chart is ready now. You can use a highlighter to mark the rows you finished or put a checkmark on them. This way it is very easy to follow decreases in increases.

Some Warnings and Tips

We know that raglan increases and decreases look very good on our sweaters, jumpers, cardigans, etc. We just need to be careful about some points while making them. Here are some suggestions which I have experienced and learned from my knitting projects:

  • Write down every detail while you are making calculations and write them in an organized way. Most of the time, I plan a raglan cardigan or sweater and take the pen and paper closest to me to write down the numbers. Later, I lose it or get confused with which number is for what. Do not make that mistake. Carefully write the numbers and what they represent. Moreover, if you are like me and work on more than one project at a time, name the projects so that you do not mix up the numbers of various projects.
  • Don’t start decreasing from the first stitch. The first stitch is a little complicated. Some knitters do not even knit it and pass it on from one needle to the other. Therefore, it is not very reliable. When making decreases, knit at least the first two stitches and decrease the 3rd and 4th. This way, your seaming will look smoother and it will be easies for you to follow what you have done. This is not an issue for top-down projects since they are worked as round. For others, leave that first two stitches alone.
  • The decreases must be the same for all pieces. Whether you are making a sweater, jumper or a cardigan, the separate pieces should be decreased with the same fashion. Remember our scheme? You need to use it for each piece. Since, you need to make decreases in the same rows of all pieces. If you are using the scheme, make as many copies as your pieces. Use separate copies not to get things mixed up.

These are the methods I use and know, and the tips and tricks I learned along the way. If you have anything to add, correct or discuss, please feel free to contribute.