People new to sewing often ask me about how to pick the right pattern size. Most of the confusion stems from trying to correlate their RTW size with the commercial pattern size. But RTW sizes aren’t even remotely consistent so they’re no help.
Exhibit A from the NY Times:
IN SHORT, DO NOT DO THIS TO YOURSELF!
Vanity sizing is making people crazy. I mean, I’m writing about this. I studied it. Yet slipping into a size I KNOW I don’t really fit still makes me feel a little pleased with myself. But commercial patterns don’t work that way. You might wear a 6 at your favorite chain store, but have to use a size 10 pattern – and you have to be okay with that or you’re going to make yourself miserable trying to make your garment fit.
The most important measurement you need when you’re picking out a jacket, blouse, top or dress pattern is your bust measurement. For skirts and pants, use your hip measurement (unless the skirt is an A-line, then use your waist measurement.) I need you to trust me on this one: adjustments below the waist are usually much easier than fiddling around with the torso.
Most people choose their pattern size from their full bust measurement, but you should take both the full and overbust measurements. If the difference is over 2 inches, choose the pattern using your overbust measurement. You can take it by putting the tape around your torso under your arms and over the top of your bust, like this:
Why is that you ask? Because the Big 4 patterns are based on a B cup. If you’re say a 32D, and you go by your full bust size, the back will be much too wide and the shoulder seam will be way off.
If you’re above or below a B cup and your pattern is somewhat fitted, you’ll probably need to do either an SBA (small bust adjustment) or FBA (full bust adjustment). I’ll do a post about the FBA in the near future as it’s an adjustment I have to do regularly.
Now these are just general guidelines, but I hope this helps clear up some of the confusion about choosing the correct pattern size and saves you from making some of the same mistakes I did when I started sewing.