Fabric Weight Converter
Convert fabric weight between GSM and oz/yd².
Covers lightweight, midweight, and heavy fabrics for apparel, upholstery, and technical textile sourcing.
Type in either field — the other updates instantly.
Fabric weight describes how heavy a fabric is per unit area. It is the most common way to compare fabric thickness and quality.
GSM (grams per square meter) is the international standard. oz/yd² (ounces per square yard) is used mainly in the US.
Conversion formula:
- GSM = oz/yd² × 33.906
- oz/yd² = GSM ÷ 33.906
Common fabric weights:
| Fabric Type | GSM | oz/yd² |
|---|---|---|
| Chiffon, voile | 30–70 | 0.9–2.1 |
| Cotton shirting | 100–150 | 2.9–4.4 |
| Denim (lightweight) | 150–200 | 4.4–5.9 |
| T-shirt jersey | 150–200 | 4.4–5.9 |
| Sweatshirt fleece | 250–350 | 7.4–10.3 |
| Denim (heavyweight) | 350–500 | 10.3–14.7 |
| Canvas | 400–700 | 11.8–20.6 |
Quick guideline:
- Under 150 GSM: lightweight (blouses, linings)
- 150–350 GSM: medium weight (t-shirts, dresses, pants)
- Over 350 GSM: heavyweight (outerwear, upholstery)
GSM (grams per square meter) is the global standard for fabric weight, while the US textile and clothing trade often uses ounces per square yard. Both measure the same property in different units, which is why a conversion helps when a supplier’s spec and a buyer’s expectation don’t match. Watch the “per square yard” part, though: it’s an area weight, not the linear ounces-per-yard used for some narrow goods, and mixing the two gives nonsense.
Weight is a quick proxy for how a fabric behaves. Lighter fabrics drape and breathe; heavier ones are sturdier and warmer but stiffer. For t-shirts the number has turned into a marketing point, with “heavyweight” 200+ GSM tees prized for durability. But heavier isn’t automatically better: a breathable 150 GSM summer tee suits its job better than a thick one would, so match the weight to the purpose rather than chasing the biggest figure.
How we build and check this converter
This converter runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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