How to Measure Yourself for the Right T-Shirt Size

T-shirt sizing is not standardized. A "large" from one brand can be nearly identical to a "medium" from another, which means the size label on its own doesn't tell you much. The fix is to stop relying on the label and start relying on actual measurements — either your own body or a shirt you already own that fits the way you want. This guide covers exactly how to take those measurements and how to use them against a size chart, which pairs well with our broader plain white t-shirt buying guide if you're shopping for a basic tee and want to get the fit right the first time.

What you need

A soft, flexible measuring tape — the kind used for sewing, not a rigid metal tape measure — is the only tool required. If you don't have one, a piece of string held against a ruler afterward works as a substitute. You'll also want a mirror or a second person to help, since some of these measurements are hard to read accurately on yourself from above.

Measuring your chest or bust

Wrap the tape around the fullest part of your chest or bust, keeping it horizontal all the way around your back. The tape should sit snugly against your body without pulling tight or compressing anything — you're measuring the actual circumference, not squeezing for a smaller number. Keep your arms relaxed at your sides while you do this, and take the reading where the tape meets itself in front. It helps to breathe normally and measure at the end of an exhale rather than holding your breath, since that tends to inflate the number slightly.

Measuring body length

Body length is measured from the highest point of the shoulder, next to the base of the neck, straight down to wherever you want the hem to sit. Stand naturally rather than stretching upright, and keep the tape vertical rather than following the curve of your torso. This number matters more than people expect: it's a common reason a shirt fits fine across the chest but still feels wrong, either riding up when you raise your arms or hanging lower than you'd like.

Measuring shoulder-to-shoulder

This one is easier to get accurate with help. Measure in a straight line from the edge of one shoulder to the edge of the other, across the back, at the point where your shoulder meets your arm. If you're doing this alone, feel for the bony point on each shoulder and try to keep the tape flat rather than dipping into the curve of your neck or back. Shoulder width is the measurement most directly tied to how a shirt sits at the seam — too narrow and the seam pulls in toward your neck; too wide and it droops past your actual shoulder onto your arm.

Comparing your numbers to a size chart

Once you have chest, length, and shoulder measurements, check them against the specific brand's size chart rather than a size you've worn elsewhere. Most charts list a range for each size — for example, a chest measurement between certain inches — and you want your number to fall comfortably inside that range, not right at the edge. If your chest measurement sits between two sizes, decide based on how you want the shirt to fit: sizing up leans looser, sizing down leans closer to the body. Pay attention to length and shoulder numbers too, not just chest, since a shirt can technically fit your chest size while still being cut too short or too broad through the shoulders for your frame.

An easier option: measure a shirt you already own

If taking body measurements feels awkward or you're not confident in the numbers, there's a simpler approach: lay flat a t-shirt you already own and love the fit of, and measure that instead. Lay it on a flat surface, smooth out any wrinkles, and measure straight across the chest just below the armpits (then double that number for full chest circumference, since a flat-lay only shows half), from shoulder seam down to hem for length, and straight across the shoulder seams for shoulder width. This method sidesteps a lot of the guesswork in measuring a body, since you're comparing garment to garment, which is usually a more direct match to a new shirt's size chart. It's especially useful when shopping for unisex-fit tees, where body measurements alone don't always translate cleanly to how a specific cut is going to sit.

A few practical notes

Measure yourself at a normal, relaxed moment rather than right after a workout, when your chest and shoulders read slightly larger than usual. If you're between two sizes, think about whether you prefer things fitted or roomy generally — that usually matters more than a half-inch difference in the numbers. And if a brand runs noticeably small or large according to reviews, factor that in on top of the chart; measuring correctly doesn't override a brand's known sizing quirks.

Getting these three numbers right — chest, length, and shoulder — and checking them against the actual size chart instead of a remembered size is the most reliable way to avoid a return. For more on choosing a well-made shirt once the size is settled, see our full library of t-shirt guides.