How to Alter Knitting Patterns

So often in knitting books, they tell you simply to add more stitches to make an item wider.  They don't really get into actually fitting knitted garments, because "knitting stretches and is forgiving".  Wanna bet that was written by a man, or a B cup lady?

Ever chose your sweater size based on the chest size (often the only measurement given), knit up the item and been so disappointed?  You check the measurement--yup, it's 42" around.  You check yourself--yup, you're still 40" around.  So why is it sagging in the back and stretched thin over your chest?

Do a quick check.  Circle your chest with a tape measure, with the 0 at a side seam.  Go around your back and note what it says at the other side seam.  Continue over your bust, and note the finished 40".  Was your back measurement half of that?  No?  Your back was 16"?  So that would make your front 24"?  Look at your sweater.  The back and front are both 21".  The designer assumed you were shaped like a 0 but really, like most women, you're shaped like a D.  The extra width in the back just sags, while the knitting is forced to stretch 3" extra across the front, before accounting for any ease (which should have been one inch, so really, it should have stretched 4").  This is a lot to expect of many yarns!

Here is a step by step guide to getting started on fixing this common fitting issue!

Step 1) Measure the "Upper Bust"--around the chest, tight under the armpits, above the breasts. So don't wear your sexiest push up bra. Wear whatever you expect to wear under the garment you're making.
Step 2) Have a friend measure from the shoulder seam to where you want the bottom to be. Mark this with a pin on your side.
Step 3) Have friend measure your front length, from same point on shoulder, over the fullest point of the bust, to the same length as marked on your side. If it's close fitting, bring the tape measure in to reflect that (not too much, but an inch can change it from a fitted look to an oversized look).
Step 4) while doing step 3, mark where the bust point is and how far down from shoulder.
Step 5) Measure from side seam to side seam across the bust point. Also measure how far apart the bust points are
Step 6) Measure from back side seam to back side seam

The difference between 2) and 1) tells you how much to add in short rows.

The difference between 5) and 6) tells you how much bigger your front is and you can use this to compare with 1). If they are close (half of the measurement in 1 or twice the measure of 6)) then simply choose the size that corresponds to that and add short rows for the front length. If there is a bigger size difference than what the natural stretch of knitting will allow (or if you're knitting a non-stretchy pattern/yarn), then you can play with front width. If you have a belly and no butt/hips, I would automatically go with a larger front size. Compare the bust/waist/hip measurements on the schematic to see how it compares to you. 

If you need a larger front size, you can reduce the short rows somewhat. 

You'll need to cast off under the arms and make the arm shaping decrease so that by the time you get to the shoulder seam, (using the armhole depth of the smaller size), you have the same number of stitches as the smaller size. Depending on the neck design, use the numbers for the smaller size.   Often, the depth of the armhole can be shortened a smidge too.  Often, the patterns get upsized all over, and busty girls aren't necessarily bigger in the arms.

Of course, there is much fine tuning that can be done to these guidelines. Making a "sloper" or a "block" of a basic shape that fits you, in a plain yarn that is typical of what you use, can really help cut down design time in the future. Then transfer all the info to a paper pattern for the knit radar/knit leader/knit contour.

This is a very basic starter guide, to teach when to use just short rows and when to knit the front a larger size.  Even just adding short rows to the front can make a big difference, but mostly if your front and back are close in size.  However, you really should knit the back to fit your back and your front to fit your front.  A person who is "just" busty can get away with making the size to match the upper bust but adding short rows.  

A great site to learn more about adding short rows to shape the length of the front is http://www.whiteliesdesigns.com/patterns/lpullovers/fbc.html.  This basic pattern could become your sloper as it'd be easy to see where you need to make other changes.  Also take a look at sewing websites about fitting.  A sewing designer would never make the front and back of a piece equal!