The bust measurement is probably the most important measurement when it comes to making any torso garment fit a woman. Whether you’re making a sixteenth century corset, a modern jacket, or a 1960s trapeze dress, if it doesn’t fit correctly at the bust, it doesn’t fit. How do you get the right measurement?I’ve seen several methods. Here is the one I prefer, and use. (With one very specific exception, which is when I’m taking the measurements to work a moulage draft. If you know what that is, you’re probably a million years beyond the need to read any further.) To take a bust measurement properly, you need two people: one being measured, and one measuring. It’s nearly impossible to do it yourself and come up with an accurate measurement. (Trust me on this… It’s possible to get close, but you’ll get a much better measurement if you have someone who understands what’s needed helping you out.)
The victim person being measured should stand with her arms out to the side at shoulder level. The person doing the measuring should wrap the tape (the measuring kind) around the measuree, level with the bust point, and with the correct set of markings outward. (I’m constantly ending up with the metric side of the tape outward. Not too helpful when you work in inches…) Now, the term “bust point” refers to the most prominent part of the breasts. Optimally, that’s at nipple level. (I’ve noticed, over the last several years, that that doesn’t work without a bra on, so I tend to take my measurements that way. I think, especially above a B cup or, say, past your 30th birthday, that that’s the way to go. You should be wearing a bra that fits, obviously – you should be full, but not overflowing, and except for very special situations, it shouldn’t be of the padded/push-up variety. Bear in mind that any bra changes the shape, profile, and location of the breasts. If you’re making modern clothing, and using darts or a princess seam to achieve a “perfect” fit, it’s important to work all your measurements in the bra you intend to wear. This goes double in the case of wedding gowns and strapless gowns.)
The tape should be level all around the body – any dips will make the measurement read larger than the actual fact. Follow the level of the bust point all around the body. It’s possible (likely, actually) that this won’t be where the bra strap hits in back. That’s ok.
The measuree should now lower her arms, while the measurer keeps the tape held in position. This will usually increase the measurement slightly, and that’s ok, since you probably spend more time with your arms down than straight out to the side. If the measuree is, say, an operatic soprano being measured for the costume she’ll use in tragic dying aria, she should take a normal breath. The singers should inhale deeply. You now have the measurement you need.
For many patterns, it’s advantageous to know how much of the bust measurement is in front and how much is in back. (Who hasn’t stopped while patterning a corset and pondered, “How can my body really be the same shape in the front and the back? Isn’t that pretty fundamental to being a girl?”)
The side line of the body is right below the center of the armpit. To easily get a Front and Back bust measurement, start with the tape held at the side of the body. I usually put the numbers going up across the back. Go through all the normal motions to take the bust measurement (with some accommodation for the fact that there’s a hand between the measuree’s arm and her ribs.) When everything is settled, hold the tape in place on both sides of the measuree – I don’t care how you do it, so long as nothing gets tugged. Now, record the measurements: zero to the other side line – if you’ve done it like I do, this is the Back Bust measurement. The Front Bust measurement is the full bust measurement minus the back bust measurement. Trust me, taking the time to record front and back bust measurements will make you life as a pattern maker much simpler.