Underbust and Overbust: What They Mean and How to Measure Them

Key Takeaways

• Underbust is the measurement around your ribcage just below your breasts. It sets your band size.
• Overbust, or bust, is the measurement around the fullest part of your breasts.
• The difference between the two sets your cup size, about one inch per letter from A upwards.
• Measure your underbust snug and your overbust loose, with the tape level all the way round.
• Measure in an unpadded bra or no bra, since padding adds to the overbust.
• Re-measure every six to twelve months, or after any change in weight, pregnancy or feeding.

Your underbust is the measurement around your ribcage, just below your breasts, where a bra band sits. Your overbust, also called your bust, is the measurement around the fullest part of your breasts. Your underbust gives you your band size. The difference between the two gives you your cup size. For example, an underbust of 32 inches and an overbust of 36 inches is a four-inch difference, which makes you a 32D.

What Is Underbust?

An underbust, a term popularly used for bra measurements, is simply the area where your bra band fits snugly, which is the circumference of your rib cage just below your breasts.

In centimetres, a 32-inch underbust is about 81 cm and a 34-inch underbust is about 86 cm.

In Hindi, underbust is often described as chhaati ke neeche ka naap.

How to Measure Your Underband (Underbust) Correctly

Stand straight with your arms relaxed by your sides.

Wrap a soft measuring tape around your ribcage directly under your breasts, where the band of a bra sits.

Pull the tape snug and keep it level all the way round, including across your back.

Read the number in inches or centimetres. If it is an odd number of inches, round up to the next even number, so 33 inches becomes a 34 band.

Why Measuring Underbust Is Important

When you choose a bra with a well-fitted underbust measurement, such as for styles like a removable padded bra or plus size bra, it ensures just the right support, comfort and lift that your bust requires, providing proper anchoring without digging into your skin or feeling too loose.

What Is Overbust?

An overbust simply refers to the measurement that is taken around the fullest part of your breasts, such as the band area above the bust or around your nipples.

How to Measure Your Overbust Properly

Once you stand up straight, keep your arms relaxed by your side.

Wrap a measuring tape around the fullest part of your chest, usually where your nipples are.

Make sure the tape is level and not too tight or too loose, making sure it fits comfortably against your body without squeezing your breasts.

Read the measurement in inches or centimetres and round it to the nearest whole number.

The Key Differences Between Underbust and Overbust

The table below sets the two measurements side by side.

How Cup Size Is Determined Using Overbust and Underbust

Take your underbust away from your overbust. The difference in inches gives your cup size: one inch is an A, two a B, three a C, four a D and five a DD. For the full ladder from A upwards, see our guide to bra cup sizes.

Underbust and Band Size Are Not Always the Same

Your underbust is what you measure. Your band size is the number printed on the bra. Bands come in even numbers, so an odd measurement is rounded up: an underbust of 33 inches becomes a 34 band. This is the method our guides use.

Some older charts and some brands add four or five inches to the underbust before choosing a band. That is one reason the same woman can be a 34 in one brand and a 38 in another. If your size changes a lot between labels, check which method the brand's chart uses.

From Your Two Numbers to a Krvvy Size

Krvvy bras are sold in letter sizes from M to 4X. Our bra size chart shows the underbust and bust range for each one. If your two numbers fall in different Krvvy sizes, Find My Size weighs both and suggests a size.

Common Mistakes to Avoid When Measuring Your Bra Size

You may not even realise it, but you could be making the following errors when trying to measure your bra size, which can further impact the accuracy of the measurement:

Measuring the underbust at the fullest part of the chest: The underbust goes directly under your breasts, where a bra band sits. Measuring across the fullest part gives you your overbust instead and makes your band look several sizes too big.

Measuring Over Clothes: You will not be provided an accurate bra measurement if you measure over clothes, as it adds bulk, which is why it is recommended to measure directly on the skin or using a non-padded bra.

Wearing Padded or Push-Up Bras While Measuring: It is best to avoid wearing these, as these again add extra padding and volume, which can, in turn, affect your natural shape while measuring.

When Tape Is Too Loose or Too Tight: The measuring tape should be tight enough to stay in place but not squeeze you, because if it's too tight, your size will look smaller, and if it's too loose, your size will look bigger.

Not Updating Your Measurements Regularly: Our bodies constantly change as we grow older or gain or lose weight, which is why it's good to measure yourself every 6 to 12 months to make sure your bra fits well.

Frequently Asked Questions

What is the meaning of underbust?

Underbust is the measurement around your ribcage directly below your breasts, where the band of a bra sits. It decides your band size, such as 32, 34 or 36.

What is overbust?

Overbust is the measurement around the fullest part of your breasts, usually across the nipples. Some charts call it bust or full bust. Together with your underbust, it decides your cup size.

How do I measure my underbust and overbust?

For the underbust, wrap a soft tape snugly around your ribcage just below your breasts and keep it level. For the overbust, wrap the tape loosely around the fullest part of your breasts. Measure in an unpadded bra or no bra.

What is the difference between underbust and band size?

Underbust is what you measure. Band size is the number on the bra. Krvvy rounds an odd underbust up to the next even band, so an underbust of 33 inches becomes a 34 band. Some brands add inches to the underbust instead, which is one reason sizes differ between labels.

What is the underbust measurement for a 34 bra size?

An underbust of about 33 to 34 inches, or 84 to 86 cm, fits a 34 band.

Should I measure my underbust tight or loose?

Snug. The tape should sit firmly against your ribcage without digging in. A loose underbust measurement gives you a band that is too big, and the band does most of a bra's supporting.