How to Design a Crochet Cardigan and Write the Pattern in Multiple Sizes

Do you enjoy designing and making your own crochet patterns/items? Have you been wondering how to design a cardigan or where to start? In this post, I'm going to go over basic construction, sizing, and how to write up patterns for multiples sizes without actually having to make multiple sizes.

First, I'm going to tell you: I am not by any means a professional/expert crochet cardigan designer. The information below is what has worked for me and a starting point/guide that may help you in your endeavors in designing your own cardigan!

I have received many questions of how to design a cardigan. Mainly - where to start and sizing. Get ready, because I'm going to give you every bit of information I know.

I've only designed two cardigans thus far but they turned out looking like cardigans so I think I have just a bit of wisdom to share with you!

Basic Construction

This is where you want to start when you want to design a cardigan. Sketch out the basic construction you want it to be - which is basically 3 rectangles (two front panels and a back panel) plus your sleeves (which are more or less rectangles too).

Sleeves can be made in the round once you have your back and front panels seamed together or you can make them separately as rectangles, sew up the side, and then sew them onto the cardigan. I've done them both ways - I did find it easier to crochet in the round once the cardigan panels were seamed together, that way I could periodically try it on.

I encourage you to look through your wardrobe or go to the mall and look at the construction of cardigans. You will quickly see that they are (for the most part) basic shapes that you can replicate by crocheting.

Another thing to think about is, although the basic consruction/shapes are the same, there are different ways to make a cardigan. You can make it from the top down and vice versa. You can also make it from side to side, which I did for my Poppy cardigan that you can see here.

For my Heartland Cardigan, I made the back panel first and continued to crochet on the back panels for the front panels for less sewing. You can see the Heartland Cardigan here.

So you basically need to make rectangles or some sort of 4 sided shapes then seam them together.


If you use any resource for making a cardigan you need to use The Craft Yarn Council.  They have a Standard Body Measurements/Sizing Chart. They also have a Fit Chart and Length Chart, which is very very very valuable.  I was totally unaware that I had to actually ADD inches to my measurements depending on what sort of fit I wanted (ex. loose, fitted, etc). Trust me, you will want to look at this chart.

Basically, these charts tell you all the measurements you need to make your cardigan for a certain size (XS-5X).  The specific measurements I look at when designing a cardigan is bust, cross back (shoulder to shoulder), sleeve length, upper arm, and armhole depth. 

Jot down the measurements (don't forget to add inches according to the Fit chart) for the size you want to make. I usually put the measurements where I sketched out your basic construction to have a clear visual image. If you're making multiple sizes, I recommend making multiple sketches and writing down all the measurements for each size.

Writing Pattern for Multiple Sizes

Once you have made a sample/cardigan for yourself and it fits well, you may want to write up the pattern for multiple sizes. 

You probably don't want to make multiple cardigans in multiple sizes to figure out the pattern and good news for you, you don't have to!

All you need is that handy dandy sizing chart and a gauge swatch in the stitch you will be using for the cardigan. If you aren't familiar with gauge swatches, I wrote a post about why it's important and how to check it here.

Once you've made a gauge swatch, jot down how many stitches/rows in the amount of area you measured. A typical gauge swatch is 4" x 4" but I typically measure 1"-2" for my gauge (you will see why in the next paragraph).

Typically I will work on the back panel of a cardigan first. Once I figure out how many stitches I have per inch, I will multiply that by what I want the width of the back panel to be. That will give me the number of stitches I need to start my back panel.

For example, let's say for every 1" there are 3 stitches and I want the width of the back panel to be 18". I would multiply 18 x 3 and that will give me the number of stitches I need across. Make sense?

To figure out how many rows for the length of the cardigan you would do the same thing. (length in inches you want the cardigan to be multiplied by how many rows per inch from your gauge swatch).

With that being said, you will also have to figure in the multiple of your stitch. Depending on what stitch you are using, you may have work in multiples of 2, 3, 4, etc.

Example: If you stitch is a multiple of 3 and you figure you need 29 stitches to make it your width, you would then just bump that number up to 30 to make is a multiple of 3.

Factors to Think About when Designing a Cardigan

Some things you want to think about when making a cardigan are:
  • How long do I want it? 
  • What type of fit? Loose? Oversized?
  • What kind of stitch/texture do I want? Flowy? Lacy? Sturdy?
  • How do I want the front panels to look? Tapered? Flowy?
  • What type of edging do I want on the cardigan?
  • Length of sleeves
  • Do I want a solid color or color scheme?
These are just a few things you may want to think about to guide you when designing a cardigan.

How to Calculate Yardage for Finished Garment

If you are writing a pattern, you may want to list how many yards of yarn the person will need in order to make the size of their choosing. You can do this WITHOUT having to make the garment!

This blog gives you a step by step on what you need to do to calculate the amounts!

There is both a guesstimate way and a more calculated way. It's definitely a good tool to use!

Now that you have some basics on how to design a cardigan, I hope you take the plunge and give it a try! I would love to see what you come up with. Tag me on Instagram @mariasbluecrayon