What's the difference between oversized and boxy fit?
Oversized fit extends the body length and adds drape, so the tee hangs longer with a relaxed silhouette. Boxy fit keeps the body shorter and wider, so the shape reads almost cube-like, with the chest and hem about the same width and the length cropped higher. Both are loose, but they read very differently on the body.
Oversized fit, defined
Wider chest, dropped shoulder, hem that lands past the hip, sometimes well past. The visual line moves downward. It pairs naturally with wide-leg pants, joggers, and longer outerwear. The silhouette extends you.
Boxy fit, defined
Wide chest, but the body length is cropped. The hem usually lands at or just above the hip. Shoulder might be dropped slightly or set-in. The garment forms more of a square shape on the torso. It pairs with high-waisted pants, shorts, and anything where you want the waist visible.
Where they overlap
Both are loose in the chest. Both lean away from body-hugging silhouettes. Both come out of the same streetwear and skate lineage. You will sometimes see brands call the same garment oversized or boxy depending on marketing.
How to tell them apart on a product page
Look at the length measurement relative to the chest. If body length is significantly greater than half the chest width, it is oversized. If body length is close to or less than half the chest width, it is boxy.
Which suits you
Boxy works well on taller frames who do not want to add visual length. Oversized works well on most frames and pairs cleanly with high-volume bottoms. Neither is correct or incorrect. Pick by silhouette goal, not body type.