The Plaid Studio / Free tools / Fabric weight calculator
Fabric weight calculator
Fabric weight is quoted four ways — grams per square metre (GSM), ounces per square yard, and per linear metre or yard of a given width. Enter any one and get the other three, with the weight class it falls in.
The conversions
- GSM ↔ oz/yd²1 oz/yd² = 33.906 g/m². So 200 GSM is 5.9 oz/yd², and a 12 oz denim is 407 GSM.
- Per linear metreGSM × width in metres: 200 GSM at 150 cm wide weighs 300 g per running metre.
- Per linear yardoz/yd² × width in inches ÷ 36: 5.9 oz/yd² at 59 inches is 9.7 oz per running yard. Many US mills quote this one, which is why the same cloth can read heavier in a US catalogue.
| GSM | oz/yd² | Class | Typical fabrics |
|---|---|---|---|
| under 100 | under 3 | Very light | Voile, lawn, chiffon, organza |
| 100 – 170 | 3 – 5 | Light | Shirting, poplin, quilting cotton, gingham |
| 170 – 270 | 5 – 8 | Medium | Twill, chambray, flannel shirting, linen |
| 270 – 410 | 8 – 12 | Heavy | Denim, canvas, tweed, kilt tartan |
| over 410 | over 12 | Very heavy | Heavy denim, upholstery, coating, blanket |
Weight follows from the yarn and how densely it is set. The yarn count calculator works out the sett for a yarn; the fabric calculator works out how much to buy.
Questions
How do I convert GSM to oz?
Divide GSM by 33.906 to get ounces per square yard: 300 GSM is 8.85 oz/yd². Multiply oz/yd² by 33.906 to go back.
What GSM is a good T-shirt or shirt fabric?
Shirting and poplin are about 100 to 150 GSM; a T-shirt jersey is usually 140 to 200 GSM, with heavyweight tees at 220 and above.
Why does a US fabric weight look heavier?
US mills often quote ounces per linear yard of the full width, which includes the width of the cloth. Convert to oz/yd² or GSM to compare fabrics of different widths.
What GSM is denim?
Light denim is about 270 to 340 GSM (8 to 10 oz/yd²); classic jeans denim 12 to 14 oz is 407 to 475 GSM.