GSM: Fabric Weight Explained

Why GSM Matters

Fabric weight affects everything: how a garment drapes, how warm it is, how it washes, and what it's suited for. Two t-shirts can look identical on a hanger but feel completely different because one is 140 GSM and the other is 220 GSM. When you understand GSM, you can predict how a fabric will behave before you ever touch it.

Typical GSM Ranges

• Under 100 GSM - sheer and lightweight: chiffon, voile, organza. Think blouses and linings.
• 100-150 GSM - light: standard t-shirt jersey, summer shirting.
• 150-200 GSM - medium: quality t-shirts, polo shirts, light denim shirting.
• 200-300 GSM - medium-heavy: sweatshirts, heavier denim, upholstery-weight cottons.
• 300+ GSM - heavy: fleece, canvas, winter coatings, premium denim.

GSM vs Thread Count

Don't confuse the two. Thread count measures how many threads are woven into a square inch (mostly used for bed sheets). GSM measures weight per area and applies to all fabrics, knits included. For apparel, GSM is the more useful number.

GSM FAQs

What is a good GSM for t-shirts?

Most quality t-shirts fall between 150 and 200 GSM. Under 150 feels thin and may show through; over 200 feels substantial and structured.

Does higher GSM always mean better quality?

No - it means heavier, not better. A 120 GSM silk can be exquisite; a 400 GSM polyester can be poor. Match the weight to the garment's purpose.

How is GSM measured?

A circular sample of known area (usually 100 square centimeters) is cut from the fabric and weighed on a precision scale. The weight is then converted to grams per square meter.

Is GSM the same as ounces per square yard?

They measure the same thing in different units. Denim in the US is often sold by ounce weight (e.g., 12 oz denim); multiply ounces by about 34 to get the approximate GSM.