Fit & fabrics
A T-shirt sleeve that sits well on the arm
Length, opening and shoulder position work together; tightness is not the only measure.
Look at the sleeve with the arm relaxed
A sleeve that looks good while you flex in a mirror may feel quite different through the day. Let your arms hang naturally and see whether the fabric falls, clings or flares. The sleeve opening should suit the intended shape of the T-shirt rather than demonstrate a particular amount of muscle.
A short narrow sleeve creates a different outline from a wider sleeve reaching nearer the elbow. Both can work. Compare them with the body width and shoulder seam: a broad, boxy shirt with tiny tight sleeves may feel inconsistent, while a deliberately relaxed tee often carries a wider sleeve naturally.
Move before judging the size
Reach forward, lift your arms and bend your elbows. Check whether the sleeve catches high on the arm or twists at the seam. Some movement is normal, but constant readjustment suggests the cut is not working for you. A stretchy fabric can conceal tightness while standing still without making the fit comfortable.
If the sleeve is restrictive, try a different cut as well as a larger size. Sizing up may add unwanted length through the body while leaving the sleeve shape surprisingly similar. Look at the armhole and shoulder too; the problem may begin above the part that feels tight.
Consider what sits over it
Try the T-shirt beneath the overshirt or jacket you use most. A thick rolled cuff can create a ridge under a closer sleeve. A long loose sleeve may fold back on itself during layering. If you regularly wear the shirt alone, those concerns may matter less than how it balances with your trousers.
Do not rely on repeatedly rolling the sleeve to rescue a cut you dislike. A casual turn-up can be intentional, but check whether it stays in place without becoming a tight band. Before buying several colours, wear one version through ordinary movements if the return conditions allow an appropriate try-on. The useful fit is the one that remains comfortable when you stop watching it, not the one that needs a fixed pose to look right.
