Sizing Knitting Patterns
Article by KarensVariety.com

When you look at a knitting pattern and are trying to select the size to make you have to consider many things.

When choosing a knitting pattern, we tend to look first at the picture, just as we look at clothes on the rack in a store. We have a fairly good idea of what will be flattering and what we simply can not wear or do not like. Just as in a store, we can be surprised when we try on our choice and see that it looks quite different than it did on the hanger or in the picture. Of course, in a store we simply try on something else. With knitting, it pays to be more careful before we begin knitting.

Patterns give certain description clues; fitted, semi-fitted, loose fitting, oversize. These words give us an idea of the final look we will achieve. The type of pattern we choose also gives us an idea of the finished product. Set-in sleeves give a more tailored look; raglan or drop sleeves are more casual. You may wish to wear a blouse or camisole underneath the sweater. This will make it look tighter than you plan. Is it a straight style or pinched at the waist? Are stripes vertical or horizontal? When you look at the picture on the model, have a closer look at each feature and analyze whether that feature is flattering to you.

Patterns often dictate which yarn brand and type to use. You can substitute different yarns but be sure to choose a yarn you are familiar with. All have different qualities. If you choose a pattern that is fitted, you may not want a yarn that is quite stretchy. A lightweight sweater should not be knit with a heavy yarn.

Some patterns state multiple sizes; Small, Medium, Large or bust/chest size in inches/cm. Others give the Finished Measurement of the garment. By comparing these two measurements you can determine how closely the garment fits; how much "ease" there is. Take your bust/chest measurement and add a number of inches to it to determine the fit.

For example, if the pattern has a gauge of 10 stitches per inch and you knit a swatch that has 11 stitches instead, the size of the finished garment will be quite different.

Each row in the pattern knits over 300 stitches.
According to the gauge of 10 sts = 1 inch, these 300 stitches create a width of 30 inches
(300 sts divided by 10 sts)

Your gauge knits 11 sts = 1 inch so these 300 stitches create a width of 27 inches
(300 sts divided by 11 sts)

The size on a pattern will give you a rough idea of the size but knitting a swatch is the more important way to be sure of sizing.

To make your pattern size bigger, knit a swatch, divide the number of stitches by the pattern size and multiply it by the size you wish.

In the above example, you would divide 30 inch width into 300 inches = 10 stitches to the inch and then multiply it by the width you wish.  
300 / 30 = 10  then by your width, eg 36 = 360
So you will require 360 stitches instead of 300 stitches to get the width you wish.

To make your pattern size smaller, knit a swatch, multiply the number of stitches per inch by the width you wish.
10 x 36 = 360

You will need to adjust increases and decreases using the same formula.