T-shirt size in figures

Short answer: A T-shirt is chosen by chest width. The length follows the size, and shoulder width is the measurement that decides whether it can be worn at all. Know those two and most of the choice is already made.

Chest width is the main measurement

When you look for your T-shirt size, start with chest width. Size charts are built on it, and it is where a T-shirt most often feels tight or loose. Once the chest is right, you have a safe starting point. The other measurements are for fine tuning afterwards. See bamboo underwear for women.

How to measure your chest

Measure around the widest part of your chest with your arms down. Keep the tape level all the way round, including across the back, where it tends to slip. Breathe normally and do not pull the tape tight. It is easiest with help, but a mirror works too. Write the number down right away.

Shoulder width cannot be changed

Shoulder width is the one thing the fabric cannot fix. A seam that sits out on the upper arm cannot be moved, and it makes the whole T-shirt look too big, even when the chest fits. A size that fits the chest but not the shoulders is the wrong size. See women's bamboo joggers.

How to check the shoulder seam

Put the T-shirt on and stand in front of a mirror with your arms down. The shoulder seam should sit where the shoulder ends and the arm begins. If it hangs on the upper arm, the size is too big. If it sits in on the shoulder and pulls, it is too small. It takes seconds to check.

Length follows the size

On a standard model you cannot choose the length separately. It follows the size, and one size up usually adds about two centimetres in length. That sounds small, but it can decide whether a T-shirt covers your waistband or rides up when you reach for a high shelf. See most popular for women.

When your torso is long

With a long torso you may end up between two sizes. Your chest points to one, but the length needs the next. In that case a long torso often needs one size up. Then check the shoulder seam again, because it decides whether the larger size still looks right. If the shoulders sit well, the choice is fine.

Compare with a T-shirt you know

The simplest check is a T-shirt you already like. Lay it flat on a table and measure across the chest just below the sleeves. Measure shoulder to shoulder and from the neck down to the hem as well. That gives you three numbers from a piece that fits, ready to compare with the size guide.

Fit over time

A T-shirt should fit when it is new and after many washes. Follow the care label in the neck and let it dry flat or on a hanger. That keeps its shape best. Do not choose a smaller size hoping it will give. The shoulders and chest need to fit from the first day you wear it.

Frequently asked questions

Which measurement do you use for a T-shirt

Chest width, measured around the widest part of the chest with your arms down by your sides. Breathe normally while you measure and keep the tape loose.

Why does shoulder width matter

Because the fabric cannot change it. If the shoulder seam sits out on the upper arm, the size is too big, whatever the chest measurement says.

How much longer is one size up

Usually two centimetres in length. The length follows the size and cannot be chosen separately on a standard model, so a long torso often needs one size up.