Standard body measurements are one of those things that every budding sewing pattern designer searches for at some point (I know I spent quite a while looking when I first started grading patterns!), and they can be tough to find. Of course, you can shell out some cash (up to hundreds!) for full sets of measurements - but if you wanted to do that, you wouldn't be here, right?! And then, there's the issue of whether or not the standards are up-to-date, correct, in the right size range, etc.
Well. Let me tell you. Your size charts can be WHATEVER YOU WANT THEM TO BE. Yes, you read that correctly - your size charts are up to you, the designer.
HOWEVER, having a set of standard body measurements is absolutely crucial in getting the proportions of your patterns just right. For example, you might use the standard bust and waist measurements for a given size, but if you are designing for the pear-shaped figure, you might increase the corresponding hip measurement by an inch or two.
In addition, establishing your own size chart is the absolute first step before beginning to grade your patterns. Without an established chart and range, you won't know how much each measurement should increase for each size, and you won't know how many steps you need to increase/decrease to create all your different-sized pieces.
So, let's jump right in.
About These Standard Body Measurements Charts I collected the information in these charts over a couple years and cobbled them together to attempt to give you a complete set of standard body measurements for whomever you're designing for - men, women, plus-size women, children, infants and toddlers. Most of the numbers come from slightly out-of-date standard body measurements that can be purchased in their current form for a hefty price. Out-of-date? Yes, out-0f-date if you consider the late 1990s and early 2000s to be out-of-date. (I don't.) The companies that compile the standards change them ever so slightly every 10 years or so in order to have a new product to sell.
Once I got all the numbers compiled, I adjusted the sizes to more closely match ready-to-wear (RTW) sizing from several of my favorite stores - Madewell, J.Crew, Garnet Hill and Banana Republic. As an example - the standard body measurements charts originally put me at two sizes bigger than what I would order from any of these retailers, so I made adjustments accordingly. If you so desire, you could make further adjustments this way or even come up with your own numbering system. So, an XS could be called size 1, and S could be called 2, and so forth and so on.
Finally, I converted all the fractional measurements into decimals so the numbers would be ready for you to plug into Illustrator. And finally finally, I filled in some missing pieces from various other sources to hopefully give you all the measurements you need. If you DO find you are missing something, you can often use the included standard body measurements to piece the rest together. So, if you needed the distance from the cervicale (lowest vertebrae of the neck) to the hip for a top pattern, you could subtract the head & neck height and the hip height from the overall height to calculate that amount. When in doubt, I draw a picture. Works every time.
Determining Your Patterns' Size Range The size range for which you will create your size chart is totally up to you. You might notice that sizes will increase pretty evenly from, say, 12mos through 4T, and then they start increasing more between sizes. You might choose to create separate patterns based on those increments, or you could base your size selection on the style/fit of the garment. Like I said - completely up to you. Also keep in mind that there's a huge opportunity for someone who is willing to design plus-size patterns. I highly encourage women's pattern designers to go up to and above size 14 when grading (keeping in mind some proportion changes which I'll discuss more below).
Even vs. Uneven Grading Generally speaking, there are two ways to grade in-between sizes: even or uneven. Even grading means that the sizes are incrementally increased/decreased at an even rate - so, the bust might increase 1" between every size. At some point, your pattern might start increasing at 1.5" (or whatever), but generally speaking, the grade is even. Uneven grading means that you base your pattern pieces more on exact standard body measurements - so one size might increase .75", the next .5" and the next 1.25". The method you use is also up to you, but I personally prefer to use even grading. It's must easier to digitally grade, and I just think it looks prettier on paper.
Or, you can do a combination of the two - the best method for offering an extended range of sizes. For example, if your size range includes from a women's 2 through 24, you might only increase 1" in the bust for sizes 2 through 14. Beyond that, you might increase at a larger rate of 1.25" or 1.5". In addition, the proportion for the waist might change at the higher end of the range, so you might create a break point in your size range where the grade changes. If the sizes 2-14 usually have 10" difference between bust/hips and waist (just an example), your sizes 16+ might have only 8" or even 6" between them. You get the make the judgment call and then test the fit as desired.
Ready for those standard body measurements? I hope this has given you a quick overview of how you can utilize these standard body measurements in your pattern designs. I'm sure there are some topics within this area that you'd like me to discuss further, so please leave comments with questions and ideas! I will do my best to cover any issues.
Quick note: I didn't write out a detailed explanation of each of the measurements in these charts. I figured that if you are at the point of designing patterns, you can probably figure them out. Please do let me know if this is something you really need though! Also note that the centimeter/inch measurements don't always convert exactly because of rounding.