How to measure your chest

Short answer: Chest size is measured horizontally around the widest part of the ribcage. The tape should lie flat without pulling tight, and you should breathe normally while you measure.

Horizontally around the widest point

The tape must sit at the same height all the way round, including at the back. For most people the widest point is just under the armpits and across the chest. If the tape slips down at the back, the measurement is wrong. It matters most for close fitting pieces like men's bamboo undershirts, where there is little room to spare.

Without pulling tight

A tape that pulls tight gives a measurement two centimetres too small. That does not sound like much, but it can be the difference between two sizes. The tape should lie flat against the body and follow it without pressing in. You should be able to slide a finger under it without effort.

Breathe normally

Measure on a normal breath out, not with lungs full and not with your stomach pulled in. A measurement taken on a deep breath comes out too large, and the clothes end up loose. Stand relaxed with arms by your sides and look straight ahead. That is how you stand most of the day.

A thin layer or nothing

Measure directly on the skin or over a thin layer. A thick jumper or a shirt with pockets can add several centimetres and make the measurement useless. Even for a sweatshirt or a hoodie, you measure the body and not the clothes you are wearing. The difference between a close and a loose fit lies in the cut.

Get help if you can

It is hard to keep the tape level at the back on your own. Ask someone to hold it, or stand in front of a mirror and turn a little so you can see the tape is straight all the way round. Measure two or three times and use the figure that repeats.

Compare with the size guide

Once you have your measurement, compare it with the size guide on the product page. If you fall between two sizes, the choice depends on how the piece should fit. An inner layer can sit close, while a sweat for relaxed days can go a size up. See bamboo sweat for men and women and read the guide for each model.

Think about the whole outfit

The chest measurement says a lot about how a top fits, but not everything. Length and sleeves matter too. When the top fits, the rest of the outfit is easier to put together, right down to details like bamboo socks. A good measurement saves you returns.

Measure again now and then

Bodies change over time, and so do measurements. Measure again if it has been a while, or if clothes that used to fit start to feel different. Write the figure down somewhere you can find it, such as your phone. Then it is to hand the next time you shop.

Frequently asked questions

Where do you measure the chest

Horizontally around the widest part of the ribcage, with the tape at the same height all the way round, including at the back where it slips most easily.

Should you wear clothes when measuring

Only a thin layer or nothing. A thick layer adds several centimetres and makes the measurement useless for choosing a size.

How tight should the tape be

Flat against the body without pulling. You should be able to slide a finger under the tape without effort while breathing normally.