Fabric GSM Calculator
Convert fabric weight between GSM (g/m²) and oz/yd², and see what that weight means for your garment.
1 oz/yd² = 33.906 gsm
GSM is weight per area, not thickness: a dense thin fabric and a lofty thick one can share a GSM. Thickness and hand are on the item specification, and the swatch book is how you feel them.
Fabric weight guide
| Weight range | Feel | Typical fabrics | Typical garments |
|---|---|---|---|
| Up to 100 gsmUp to 2.95 oz/yd² | Sheer and floaty | Chiffon, Organza, Voile, Gauze | Blouses, Partywear |
| 100–150 gsm2.95–4.42 oz/yd² | Light shirting | Poplin, Challis, Single Jersey, Chambray | Shirts, Dresses, Lining |
| 150–250 gsm4.42–7.37 oz/yd² | Midweight | Twill, Ponte, Pique, Denim | Trousers, Outer, T-shirts |
| 250–350 gsm7.37–10.32 oz/yd² | Heavy mid | Denim, French Terry, Canvas, Tweed | Jeans, Sweatshirts, Suits |
| 350 gsm and over10.32 oz/yd² and over | Heavyweight | Fleece, Sherpa, Melton, Velvet | Coats, Cargo Pants |
Every fabric here lists its exact gsm, width and composition, so you can filter by the weight you need.
Browse fabrics by weightGSM FAQ
How do I convert GSM to oz/yd²?
Divide gsm by 33.906. 200 gsm ÷ 33.906 = 5.90 oz/yd². To go back, multiply ounces by 33.906.
What weight is used for t-shirts?
Most t-shirts use 140–200 gsm single jersey. Lighter drapes more; heavier holds its shape.
What counts as heavyweight?
From around 300 gsm — about 8.85 oz/yd² — upward: heavy denim, fleece, canvas and coating weights.
Does gsm tell me how thick a fabric is?
GSM is weight per area, not thickness: a dense thin fabric and a lofty thick one can share a GSM. Thickness and hand are on the item specification, and the swatch book is how you feel them.