Buying t-shirts online remains one of the most common sources of returns in fashion e-commerce, and the culprit is almost always sizing. A shirt that looks perfect in a photo can arrive too tight across the shoulders, too short in the body, or so boxy it loses all shape.
Learning to read a size chart properly, and understanding how different brands and cuts vary, can save you the hassle of repeated returns and help you order the right fit the first time.
Start With Your Own Measurements, Not Just Your Usual Size
The single biggest mistake shoppers make is assuming their size label (S, M, L, XL) means the same thing across every brand. It rarely does. Instead, measure yourself directly: chest circumference at the fullest point, shoulder width from seam to seam, and desired body length from the top of the shoulder to where you want the hem to fall. Keep these three numbers saved somewhere so you can compare them against any brand’s size chart in seconds.
Always Check the Garment Measurements, Not Just the Size Label
Reputable online retailers provide a size chart with actual garment measurements in centimetres or inches, not just S/M/L labels. Compare these numbers directly to your own measurements rather than relying on the size you normally buy in-store, since cuts and shrinkage rates vary significantly between brands and even between different product lines from the same brand.
Understand the Difference Between Fit Types
Product listings often describe a fit as regular, slim, relaxed, or oversized. These terms are not standardised across the industry, so it helps to look at the actual garment measurements alongside the fit description. A slim fit from one brand might be roomier than a regular fit from another. If a product page includes a model’s height and the size they are wearing, use that as a rough visual reference point.
Factor in Fabric Behaviour
100% cotton shirts tend to shrink slightly after the first few washes, typically around 3-5%, unless pre-shrunk. If a shirt fits perfectly straight out of the packaging, it may end up snug after laundering. Blended fabrics with polyester or elastane hold their shape better and shrink less, which is worth considering if you tend to size exactly to your measurements rather than leaving room.
Read Reviews for Fit Feedback
Customer reviews often include specific comments about whether a shirt runs small, large, or true to size, information that is far more reliable than the size chart alone, since it reflects real-world experience rather than the manufacturer’s intended measurements.
When in Doubt, Size Up for Comfort
If you are between two sizes and unsure, sizing up is generally the safer choice for t-shirts, since a slightly looser fit still looks intentional, especially with the current popularity of relaxed and oversized silhouettes, whereas a too-tight shirt is uncomfortable and difficult to style. The exception is shirts you intend to tuck in regularly, where a closer, true-to-size fit usually looks cleaner.
Taking a few extra minutes to measure yourself and compare against a brand’s actual size chart, rather than guessing from a familiar label, is the single most effective way to stop wrong-size returns before they happen.