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bra size calculator

Bra sizing calculators have been around for a while. They’ve done a pretty good job of helping women get an idea of what their bra size could be, but they’re far from perfect.

Let’s discuss the pros and cons of using an online bra fitting calculator:


Bra fitting calculators are great for two purposes: (1) they provide an estimate of what your bra size could be, thus narrowing down size options and giving you a better starting point, and (2) there are a few that are capable of determining your bra sister size, which consists of two different bra sizes that have relatively the same cup volume as your regular bra size.

I think it’s important to mention that there are certainly more sophisticated bra sizing calculators out there that use consumer data and algorithms to predict your bra size, but the majority of calculators online are pretty basic.

In fact, most online calculators only ask for two or three of the following measurements – your overbust measurement, your chest measurement, and your underbust measurement. The overbust measurement is measured comfortably at the fullest part of the bust with the tape measure parallel to the floor. The chest measurement is measured directly under your armpits and above your bust with the tape measure wrapped around the body horizontally. The underbust measurement is measured under the bust with the tape measure again parallel to the floor.

Once you’ve inputted your measurements into the calculator, the calculator then provides a possible bra size based on the numbers given. While it might seem simple and easy, this is the point where bra fit problems typically tend to occur and one of the reasons why you can’t rely on a bra fitting calculator alone to determine your bra size.

Related: Bra Sizing Explained: Here’s How Bra Sizing Works


Remember: bra fitting is NOT an exact science. Your bra size is determined by several different factors – your breast shape, breast size, breast root height, and breast root width among them – and bra sizing calculators do not always guess the correct bra size. Instead, they are designed to give you an idea of what your bra size could be.

Here are a few more cons to consider:

1.  It’s easy to measure incorrectly at home

If it’s your first time measuring your bra size, you might accidentally measure over a sports bra, minimizer bra, or push-up bra. These bra styles can skew measurements and give you an inaccurate bra size.

It’s best to measure your bra size in front of a mirror while wearing an unpadded wire bra that currently fits well. You also have to make sure to adjust the bra before measuring, which is often an overlooked step. You can’t simply put the bra on and measure – you have to make sure first that the straps are adjusted and the band is as parallel to the floor as possible. This will help you get a more accurate measurement, but it could still be off.

2.  You might have trouble filling out the questions

Let’s say you’re turning to an online bra sizing calculator because you’re shopping for new bras to replace your old worn-out ones. You think you wear a certain bra size, but you’re not entirely sure because your weight has changed since you last bought bras and your current bras are anything but uplifting. What if you’re not able to answer questions on band fit and cup fit? What if you don’t know what a well-fitting bra looks like? These questions can be difficult to answer. Plus, asking for your current band size and current cup size won’t help you much if you’re currently wearing the wrong size bra.

3.  Bra sizing calculators do not replace a bra fitter

Bra fitters are experts in bra sizing and fit. Their job is to help women just like you who are shopping for new bras. Plus, they know how different brands fit and can introduce you to brands you never would have tried before. And, they know exactly which bra styles will work best for your breast shape and budget.

If you want to save yourself the trouble of ordering a bunch of sizes and returning the bras that don’t fit, take a trip to your local lingerie store. Not only are the bra fitters there incredibly knowledgeable, but they’re also trained to help you find bras that fit well and feel good. How amazing does that sound?

Related: 3 Important Factors That Determine Your Bra Band Size

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Whether you’re shopping for new everyday bras or lingerie for a special occasion, it’s always a good idea to seek out a second opinion. We know how hard it is to find bras that fit well and feel good, especially when you’re doing it on your own. If you’ve ever felt unsure about your bra size or you just don’t know where to go to find good bras, it’s time to let a bra fitter help.

Many specialty lingerie boutiques offer bra fittings. Their expert bra fitters will take the pain and frustration out of bra shopping and do all the work for you. Even better, their product knowledge can save you time and money. Plus, they know where all of the best bras are hiding.

If you’ve struggled with finding bras in the right size, it’s time to make a change. Visit our specialty store locator to find a store near you and schedule an appointment.

Happy bra shopping!

Featured image lingerie:
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Published by

Katie Donnelly

Katie Donnelly is a full-time freelance writer, content manager, and founder of Katie Rose Creative. An experienced bra fitter, Katie has helped hundreds of people shop for lingerie. Her favorite bra is the Sandrine Plunge Longline Bra.

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