A bra fitting is the root canal of shopping. Next to trying on bathing suits (or having a mammogram) it’s one of the more unpleasant experiences you can put your boobs through, as far as I’m concerned.

Which probably explains why an estimated 75% of us are wearing the wrong size bra; it’s less stressful to grab the same old thing than to stand around half naked in a fitting room for a half hour or more while some chirpy stranger straps us into dozens of choices and prattles on about “uplift” and cleavage.

Bra size often changes when we gain or lose weight, gain or lose muscle tone, go through pregnancy, and get older. And bras themselves simply wear out. I can’t remember the last time I was measured and odds are that my go-to size has got up and went in the wrong direction. So I zip over to Nordstrom’s (any store with a decent lingerie department will have experienced fitters on staff) for a major overhaul of the underwear drawer.

You can measure yourself at home (details below), but according to experts, that’s not the best option. It’s very hard to pull the tape tight enough while attempting to exhale. It’s also hard to be objective about what’s flattering.

After stripping off my shirt while avoiding my reflection —  lovingly bathed in harsh fluorescent light that showcases every lump and bump, and not the good kind – my fitter Ms. C measures my rib cage by pulling the tape tightly around my body just below the bra line. This is the band size, and it’s about two sizes smaller than what I’ve been mistakenly wearing. Guess I should have done this a while ago. I learn that the right size band should fit snugly on the last hook and you should only be able to fit one or two fingers between the band and your back. (Is this why the boys had so much trouble unhooking our bras back in high school?? Oops, I digress.)

Ms. C doesn’t measure my cup size – I suppose years of looking at breasts gives you a pretty good idea of how big somebody is – and heads onto the floor to bring back different options.

As I try on the first few bras, Ms. C introduces me to the “scoop and swoop” method, immediately conjuring visions of Johnnie Cochran: “Scoop and swoop, or you will droop!” Basically, this means you put on the bra, lift up the breast tissue, and move it towards the outside edge of the cup to make sure all the boobage is tucked in. A little weird, but it works.

Now that she knows what size I am, she brings in several designs including some molded styles that I immediately reject on the grounds that the last thing I need is any enhancement.

Unfortunately, the store doesn’t carry much in my size (“well endowed” with a 30-inch ribcage) so I leave with only two Chantelle bras — supportive but not matronly. Once home, I have better luck shopping online, beginning with Nordstrom.com  and moving on to Bare Necessities, which stocks a wide variety of sizes and styles including many tops and bottoms that are boudoir-only if you’re feeling saucy.

If you are inclined to measure at home, here are some tips from Bare Necessities:

How to measure bra size:

Bra band – Pull the measuring tape tight across the bottom of your current bra directly under the bust, across your ribcage and around your back under your arms. If you get an odd number, round up to the next even number.

Remember that you want a bra to fit snugly on the last hook when new. As the band loosens with time, you’ll be able to tighten it by using the next rows of hooks. If the band of a new bra fits on the first/tightest hook (i.e., with no others showing) you’ve got nowhere to go when it gets too loose, so that size is too large.

Bust size – Find your bust measurement by measuring loosely around the fullest part of your bust with the tape straight across and around your back under the arms.

Cup size – Subtract your band size from your bust size and use the difference to find your bra cup size in the chart below. For example, if your bust is 38” and your band is 34” (a 4” difference), you would wear a 38 D.

That said, every woman’s body is different so you may need to experiment to find your best fit.

Size conversions

US/UK/European sizes vary above a D cup. When buying online, it helps to know what size you are in a specific brand so the website can suggest equivalent size choices.

(Bust minus band)         US                 EUROPE                    UK

NORDSTROM’S FIT QUIZ

• Does the band ride up in the back? If yes, your bra is either too large or it needs to be tightened. If it’s still too loose after you’ve adjusted the band, it’s time to go down a band size (and possibly up a cup).

• Do your breasts bulge or spill over the cup? If yes, your cups are too small and you need to go up a cup size.

• Do the cups pucker or gap? If your breasts don’t fill out the cups, your bra is too large.

• Do your straps slip and slide? If you’ve adjusted your straps and they still fall off, either the band is too big or your bra has lost its elasticity. If you have sloped shoulders, opt for a racerback bra or a style with convertible straps.

• Do your straps dig into your shoulders? If so, try loosening the straps. If that doesn’t solve the problem, it’s likely the cups are too small and you need to go up a cup size.

• Does the wire poke and prod? If so, you’re wearing a cup size that’s too small.

A QUICK CHECKLIST

TOO SMALL

• Spillover on top or sides
• Center section doesn’t lie flat
• Underwires poke or ride up

TOO BIG

• Cups wrinkle or gap
• Adjusted straps still slide off
• Band rides up in back

JUST RIGHT

• Smooth cups
• Center section lies flat
• Band is low and even

Interesting discovery: As band size goes down, cup size often goes up, e.g., the cup size of a 32 D will fit about the same as that of a 30 DD.

Need some wardrobe inspiration? Try one of these styles:

T-SHIRT: Smooth coverage with molded cups and enhanced lining so you can wear something sheer without any see-through.

PUSH-UP: Padding enhances cleavage and provides extra lift for plunging necklines. For less ooh-la-la, go up a cup size.

DEMI: A straight-across cut enhances cleavage, while wide-set shoulder straps highlight your neckline.

STRAPLESS/CONVERTIBLE: A fitted band provides support for any bare-shoulder look, while removable straps give you day-to-night options.

RACERBACK: This sport-inspired bra offers slip-proof straps and generous support. Great with tank tops.

BRALETTE: Soft, stretchy fabric gives light support and comfortable fit for smaller cup sizes.

UNLINED: This seamless style provides a natural shape without lining or molding and flatters an average to fuller bust.

WIRELESS: A soft, no-show silhouette works well under sheer tops and can be more comfortable than wires if you don’t need a lot of support. Foam cups offer extra coverage.

So, when’s the last time you checked if your bra is still the right size? Get thee to a fitter; it’s worth it!