What Is GSM in Clothing — And Why It Matters More Than You Think

GSM stands for grams per square metre. It’s the standard measure of fabric weight — and it’s one of the most useful numbers to understand when buying clothes, yet one of the least talked about in mainstream fashion.

Here’s a simple breakdown:

Under 150gsm — Lightweight. Breathable, drapey, and ideal for warm weather. Think summer shirts, lightweight tees, and unlined overshirts. The Donestate Plaid Colour Block Shirt sits at 120gsm — intentionally light for a relaxed, open-wear summer piece.

150–250gsm — Mid-weight. The everyday range. Most standard tees and casual trousers sit here. Comfortable across seasons with the right layering.

250–350gsm — Heavyweight. This is where garments start to carry real structure. The Donestate Barrel Leg Pants are 290gsm — substantial enough to hold their shape through the barrel-leg silhouette without stiffness. The Wide Leg Denim Shorts come in at 300gsm for the same reason.

350gsm+ — Premium heavyweight. Reserved for pieces built to last. The Donestate Vintage Wash Denim Shorts are cut from a 360gsm denim — one of the heaviest in the range — for a short that holds its structure and character over years of wear.

Understanding GSM helps you buy better. It tells you how a garment will feel, how it will drape, and how long it will last. At Donestate, every fabric weight is chosen with intention.