Oversized T-Shirt Size Guide: How to Pick Your Size

Updated October 2026

Ordering an oversized or boxy tee online is a small gamble. Size up too far and you are swimming in fabric; stay in your usual size and it might just look like a regular tee that is slightly big. Because "oversized" is a style rather than a standard measurement, an M from one brand can fit nothing like an M from another. This guide gives you a simple way to pick the right size every time, using a tee you already own and a tape measure. If you want the full breakdown of how the two shapes differ, read our boxy tee vs oversized tee guide first, then come back here to size.

Boxy vs oversized in one minute

Both fits are wide through the body with dropped shoulders. The difference is length. A boxy tee is short for its width, so it looks almost square laid flat and ends around your waistband. An oversized tee is wide and long, falling past the hips, with the shoulder seam dropping further down the arm. A boxy tee can be worn oversized by sizing up, which is exactly how many people wear ours.

Why your usual size is not the answer

Your usual size tells you how a regular-fit tee fits you. A boxy or oversized tee already has extra width built into the pattern. That means:

• Taking your usual size in a boxy tee gives you the look the designer intended.
• Sizing up gives you more length, a lower shoulder and a slouchier line.
• Sizing up twice, on a tee that is already cut wide, is usually where things go wrong.

So the question is not "what size am I?" but "how much room do I want, and where?" Measurements answer that better than letters.

The three measurements that matter

1. Chest width (pit to pit)

Lay the tee flat and measure straight across from one armpit seam to the other. This number decides how roomy the body feels. For an oversized look, you want this noticeably wider than the same measurement on your regular tees.

2. Body length

Measure from the highest point of the shoulder, beside the collar, straight down to the hem. This decides where the tee ends on you: at the waistband for a boxy look, past the hips for an oversized one.

3. Where the shoulder seam lands

This one you check on your body, not on a table. On a regular tee the seam sits on the edge of your shoulder. On a boxy tee it drops a little past it. On an oversized tee it falls further down toward the upper arm. If the seam lands near your elbow, the tee is too big, however much you like the length.

The "tee you already love" method

This is the most reliable way to size online, and it takes five minutes.

• Pick your favourite-fitting tee, the one you reach for because it hangs the way you like.
• Lay it flat on a bed or table and smooth it out without stretching.
• Measure the chest width and the body length and write both down.
• Compare those numbers with the measurements for the tee you want to buy. Choose the size closest to your favourite tee, not the size printed on its label.

If your favourite tee is a regular fit but you want an oversized look, pick a size that is a few centimetres wider and longer than it. If your favourite is already oversized, match it as closely as you can.

Sizing by the look you want

A clean boxy line

Take your normal size. The hem should land around the top of your trousers, and the body should hang straight without clinging. This is the look to go for with wide bottoms such as our baggy jorts and joggers, because the outfit has a clear break at the waist.

A relaxed oversized look

Size up one. You get more length and the shoulders sit lower. This works well with straight jeans, slimmer joggers or a mini skirt, where the extra fabric on top balances a narrower bottom half.

A neater fit if you are slim

If you are slim or narrow in the shoulders, a boxy tee in your usual size can already look generous. Consider sizing down for a sharper line.

If you are tall

Length matters more than width for you. A boxy tee will often sit higher on a tall frame, which can look intentional. If you want it to cover your waistband, size up for the length.

Body shape and comfort

A boxy tee hangs straight from the shoulders and does not cling, which many people find more comfortable than a fitted tee, whatever their shape. If you carry weight around the middle, a straight boxy hem in your usual size usually sits better than a long oversized tee, which can bunch at the hips. If you are broad in the chest or shoulders, check the chest width carefully and size for it; the length will follow.

Does cotton shrink?

Cotton can shrink slightly with hot water or a tumble dryer. Most Aurum pieces are 100% cotton, and the ROOT pieces are boxy or full cut in 100% cotton with a DTG print. Wash them cool and gently, by hand or on a gentle cycle, with a mild bar soap such as Key soap, and air-dry. Treated that way, the size you buy is the size you keep, so you do not need to size up "just in case".

Sizing our boxy tees

The Root Boxy Tee (₦19,000) has a relaxed boxy fit with dropped shoulders and room to move. It is unisex: wear your normal size for a boxy line, or size up for a bigger, oversized look. The Root Cropped Boxy Shirt (₦15,000) carries the same ROOT graphic in a shorter, boxy cut that sits well with high-waisted bottoms, so take your usual size there unless you want extra room. Both come in black, navy and white. See every shape in our oversized and boxy T-shirts.

Still unsure between two sizes? Send us your height, your usual size and the look you want before you order, and we will help you choose.

Delivery

We ship from Ibadan: ₦3,000 within Oyo State (1 to 2 days), ₦6,000 to Lagos and the South-West (3 to 5 days), ₦8,500 to the rest of Nigeria (3 to 6 days), and free on orders over ₦150,000. Worldwide delivery runs through DHL or UPS from ₦75,000, in about 7 to 10 days.

Oversized tee sizing FAQ

Should I size up for an oversized look?

In a boxy tee, sizing up once usually gives you a relaxed oversized look. In a tee already labelled oversized, take your usual size.

How do I know if an oversized tee is too big?

If the shoulder seam lands near your elbow, or the hem covers most of your shorts, it is too big.

Are boxy tees unisex?

Many are. The Root Boxy Tee is unisex, so men and women use the same sizes.

What should I wear with a boxy tee?

Wide or baggy bottoms such as jorts and wide-leg joggers, or high-waisted pieces. The short hem keeps the outfit balanced.