Fabric formula
Converts fabric area weight between grams per square meter and ounces per square yard using the exact factor 33.906.
oz/yd² = GSM / 33.906 and GSM = oz/yd² × 33.906
| Symbol | Meaning | Unit |
|---|---|---|
| GSM | Area weight | g/m² |
| oz/yd² | Area weight | ounces per square yard |
| 33.906 | Conversion factor (28.3495 g per oz divided by 0.836127 m² per yd²) | - |
Use it when a specification, mill offer or buyer tech pack states weight in ounces, which is common for denim, canvas and fabrics sold in North America.
A denim is offered at 12.5 oz/yd².
GSM = 12.5 × 33.906 = 423.8 g/m²
A 200 GSM jersey in ounces: 200 / 33.906 = 5.90 oz/yd²
One ounce is 28.3495 g and one square yard is 0.9144 m × 0.9144 m = 0.836127 m². Dividing gives 28.3495 / 0.836127 = 33.906 g/m² per oz/yd².
How to convert fabric weight between grams per square meter and ounces per square yard, where the 33.906 factor comes from, and why linear weight is a different number.
GSM is the weight of one square meter of fabric in grams. Learn how to measure it with a round cutter, calculate it from any sample size, estimate it from construction, and control it in production.