Fabric Weight Conversion
GSM and oz/yd² are the two units fabric weight gets listed in — convert between them instantly.
Rough weight-to-fabric-type reference
| GSM | oz/yd² | Typical fabric |
|---|---|---|
| Under 100 | Under ~3 | Voile, chiffon, lightweight lawn |
| 100–150 | ~3–4.4 | Quilting cotton, lightweight shirting |
| 150–220 | ~4.4–6.5 | Medium shirting, poplin, chambray |
| 220–300 | ~6.5–8.8 | Denim (bottomweight), twill |
| Over 300 | Over ~8.8 | Canvas, upholstery weight, heavy denim |
The exact conversion factor
1 oz/yd² = 33.906 g/m² (GSM), derived directly from the exact yard-to-meter and ounce-to-gram conversions — this isn't an approximation, so the numbers here match whatever a fabric's actual GSM or oz/yd² rating is.
Why fabric weight matters beyond "thick vs. thin"
Weight affects drape, structure, and how a pattern's ease reads on the body — a pattern drafted for a light quilting cotton will hang and fit differently in a heavy canvas even at the identical cut measurements. When a pattern specifies a weight range, matching it (rather than just matching the general fabric type) keeps the finished garment's silhouette closer to what the pattern was designed for.
Find It on Amazon
Search Amazon directly for fabric, notions, and sewing machine gear.