Bra Sizing Calculators

Have you ever used a bra calculator to help determine your size?

I’ve always been a bit skeptical of bra calculators – after all, you could just measure yourself and try to figure out the math on your own, and you’ll need to try on bras to figure out exactly what works best for you in any case. Even the best calculators won’t give completely accurate results for every single person. However, I’m definitely not out to bash calculators! The good ones are really a great tool – not just for those of us who are trying to figure out our correct bra size for the first time, but even for others who just want to check their current fit against a calculator. I’m also very appreciative of those who put in so much effort to create good calculators in the midst of the multitude of bad ones out there (which invariably give me something hilariously inaccurate, like 32DD).

With that said, here’s my experiences with five different “good” calculators – ones that don’t follow the dreaded +4 inches rule in regards to determining size. I’ll note that the 28GGs I’ve been wearing have been running too small for me lately, so seem to be veering more towards a 28H, or even a 26HH or so in some brands that run big in the band (most people will experience at least a little variation between brands).

[April Update: I realized that the measurements I used when I first posted this (27.5/36) were not quite as accurate as they could be. A careful remeasuring shows that my underbust measurement is 27 inches (measured firm, but not as tight as possible), whereas my bust measurement is 36.5-37 inches, depending on the bra. I’m going to go with 37 inches as that’s what I get with the bra I have that isn’t slightly too small. I also found that a 28H/HH seems to be my new current best fit.

Because of this (and the fact that some of these calculators have made some tweaks since I tested them), I’m updating the below results with these new, more accurate measurements. Do note that if you’re wearing a bra that is too small, your bust measurement may be smaller than it “really” would be if you were wearing a bra that didn’t squish you down! Even a half inch can make a difference in a resulting bra size. Also, it’s best to take the underbust measurement braless so your bra doesn’t get in the way.]

A Sophisticated Pair Calculator
Measurements entered: 27/37
Resulting size: 26H (Very Snug setting) [UK sizing]
The recently developed Sophisticated Pair calculator has been praised by many for being very accurate. It allows for decimals (no need to round) and you can select one of three settings, depending on how you like your bras to fit (Very, Moderately, or Slightly Snug). It also gives a corresponding US size result.
I do appreciate that this calculator gives 26-band results paired with a suggestion of a size that can be found more easily. In my case, it suggests a 28GG as a substitute for a 26H (the sister size). I’ve never actually had the opportunity to try a 26H, though I’ve sometimes wished to! Since the 28GG bras are running too small for me lately, I’d say that this calculator is about one cup size off for me, but still pretty close.

Butterfly Collection Calculator
Measurements entered: 27/37
Resulting size: 28H [UK]
The just-released Butterfly Collection calculator (read more about it here) has you round off your measurements to the nearest number, but it still manages to come up with a very accurate result! It also gives detailed results, depending on your preferences (starting size and looser/tighter band options, as well as different sizes to try in various brands), and gives US size results too.

Linda’s Online Calculator
Measurements entered: 27/37
Resulting size: 30I/30J [US/European]
Unlike the other calculators, Linda’s gives a US/European sizing result rather than a default UK one. The calculator doesn’t currently give under-30 band results, but I’ll assume that if it did, it would give me the sister size of the US 30I result – a US 28J – which in turn translates to a UK 28GG (see conversion chart here). Thus, although the results can be a bit confusing for those used to UK sizing, it’s really a fairly accurate result in my case – about a cup size small – when taking conversions into account!
At any rate, personally, unless a particular brand is using the +4 rule, 30 bands are too large for me. Apparently, though, Linda’s calculator will be updated so that it gives smaller band results sometime in the near future!

Electroniczny Bra Calculator
Measurements entered: 27/37
Resulting size: 28GG [UK]
I’m not quite sure where this calculator originates from, but I found it through a livejournal community several years ago.  Other features of the calculator include showing resulting bra size across 5 different sizing systems, as well as allowing you to push the results up or down in band or cup size to see the sister sizes – a handy feature. Again, it’s fairly close, though about a cup size off for me.

Curves and Corsets Bra Calculator
Measurements entered: 27/37
Resulting size: 28H [UK]
The Curves and Corsets calculator page gives a detailed explanation of how a bra should fit as well as how to measure and use the calculator, emphasizing the need to try on a range of bras rather than just relying on the calculator. It also includes a handy cup size table. The result I get from this calculator is accurate to the best of my knowledge.

So there you have it – five good bra calculators, five varying results – all within the same ballpark, though two gave what I feel is the most accurate (28H). Since sizes can vary between brands, I think it’s safe to say that no one bra calculator can solve all of your fitting problems or tell you what size you must always wear. None of these calculators claim to do so – the authors are all careful to say that these are only starting points – but I think many of us tend to want to turn to calculators to just give us an easy answer. But really, we’re all so very different – different breast shapes, body types – that we shouldn’t expect to have one simple answer that will tell us what size we should wear in every bra.

Are any of these bra calculators spot-on for you? Do you get different results for each?
What are your thoughts on bra calculators?