How long a t-shirt should be
Short answer: It should cover the waistband by a couple of centimeters when you raise your arms. Shorter and it releases your pants, longer and it looks borrowed.
The practical test
Put the t-shirt on and lift both arms over your head. The hem should still cover your waistband. If the stomach shows, the garment is too short for everyday use, no matter how well the rest fits at the shoulders and sleeves.
Why exactly this test works
Most movements throughout a day lift the upper body slightly, whether reaching up, sitting down or bending forward. A t-shirt that only covers when you stand perfectly still therefore reveals the stomach constantly in practice, not just occasionally.
What length does to your proportions
A short t-shirt makes the legs look longer and the torso shorter visually. A long one does the opposite. If it should tuck into pants, an extra long model is easiest, since it stays tucked instead of working its way back out.
The difference between front and back
Many models are cut a bit longer in back than in front. This is intentional, so the back stays covered when you bend forward. A marked difference between front and back, however, is a sign of a cut made for a different body type. See bamboo t-shirts for men.
Length after washing
A t-shirt that is just barely long enough from the start often becomes too short after two hot washes in a row. Wash at thirty degrees if length is already critical for you, and avoid hot tumble drying entirely. See bamboo clothing for men.
Length relative to body and height
The same model can look quite different in length depending on your height, because the centimeters distribute differently on a tall body versus a short one. Always try the model on if you are unsure, rather than relying only on the stated measurement.
How to choose for different purposes
For work and everyday wear, a t-shirt that just covers the waistband is usually the most practical. To wear over pants as a loose outer layer, a slightly shorter model can look better. See bamboo t-shirt for women for both cut types.
When a t-shirt is worn as a base layer
Worn under a sweater or shirt, length matters less visually, but it should still stay tucked in without constant adjusting. A too short model easily creeps up and creates a visible edge showing through the outer layer.
Alteration if the model does not fit
If a t-shirt is too long, a tailor can shorten it from the bottom fairly cheaply. If it is too short, there is sadly rarely a fix, unless you deliberately choose a layered look with another piece underneath.
Frequently asked questions
How much shorter does it get in the wash
At thirty degrees almost nothing, typically under a centimeter. At sixty degrees or in a hot dryer, it can become a couple of centimeters, which is clearly noticeable on a model that was already short.
Should a t-shirt cover the rear
Only if you specifically want that look as part of your style. For everyday use, it is usually enough that it covers the waistband, without reaching further down than that.
What if it is too long
A tailor can shorten it from the bottom cheaply and quickly on most models. This is one of the easiest alterations to have done, compared to changing sleeves or shoulders.
