The most useful starting point for gym shirt sizing is often a shirt you already own. A garment that fits the way you like gives you something concrete to compare with the size guide, instead of relying only on a letter printed on a label.
Choose a genuinely comparable garment
Use a shirt with a similar cut to the one you plan to buy. Lay it on a flat surface, smooth out wrinkles, and avoid stretching the fabric. A tight compression top is not a good reference for a relaxed cotton shirt, and a sleeveless tank is not a reliable reference for a hoodie.
Notice why you like the fit. Is there space through the torso? Does the hem stay at a comfortable length when you raise your arms? Those preferences help you interpret measurements instead of treating the size chart as a recommendation for everyone.
Compare width and length in the same units
Measure across the shirt beneath the armholes for its flat width. For length, compare the shoulder-to-hem measurement with the guide’s stated method. Keep your measuring tape straight and record the numbers before opening the chart.
A flat garment width is not the same as a body chest measurement or a full circumference. Compare like with like. The club’s size guide offers inches and centimeters, so choose one system and use it consistently; do not compare an inch measurement with a centimeter value.
Check the exact style before confirming
Size charts can differ by garment. Review the guide for the style you are considering and consult the product details when available. Do not transfer a shirt measurement directly to a hoodie or assume every product shares identical sizing.
Made-to-order purchases do not come with ordinary size exchanges under the club’s current policy. If your measurements leave you uncertain, contact the club before buying. Existing members can change their saved size through account subscription management before the next rebill for the next shipment.