How to use the fabric weight unit converter
- Enter the fabric weight and choose its unit: grams per square meter, ounces per square yard, or momme.
- Optionally enter the fabric width in inches or centimeters to see the weight of one yard or meter of cloth at that width.
- Read the weight in all three units, then the weight per linear meter, per linear yard in ounces and per linear yard in pounds.
- Use the presets for denim, silk and jersey as starting points.
Formula
1 oz = 28.349523125 g and 1 yd = 0.9144 m, so 1 oz/yd2 = 28.349523125 / 0.83612736 = 33.9057 g/m2
momme x 4.3056 = g/m2 (the common factor for silk)
weight per linear meter = g/m2 x width in meters
ounces per linear yard = oz/yd2 x width in inches / 36
Weights are converted through grams per square meter, so any unit can be converted into any other.
Ten-ounce denim, 58 inches wide
10 oz/yd2 = 10 x 33.9057 = 339.06 g/m2, which is 78.75 momme. At 58 inches (1.4732 m) wide, one linear meter weighs 339.06 x 1.4732 = 499.5 g, and a linear yard weighs 10 x 58 / 36 = 16.111 oz, or 1.0069 pounds.
A 16 momme silk is 16 x 4.3056 = 68.89 g/m2 or 2.032 oz/yd2, and 45 inches wide it weighs 78.7 g per linear meter. A 200 g/m2 jersey 150 cm wide is 5.899 oz/yd2 and weighs 300 g per linear meter.
Which unit is used where
Weight per area is the usual way to compare fabrics because it does not depend on how wide the bolt is. Grams per square meter (GSM) is common in knit and apparel specifications. Ounces per square yard is common for denim, canvas and upholstery. Momme is used for silk. Weight per length depends on the width, so it is useful for shipping and costing a roll but not for comparing two fabrics of different widths.
For paper weights, see the paper weight converter. To plan yardage for a project, use the fabric yardage calculator, and for yarn, the yarn yardage calculator.
How exact is a fabric weight?
Weights printed on a bolt are nominal. Mills weigh finished fabric with some tolerance, and finishes, washing and relaxation change it. Treat a conversion as a way to compare labels, not to predict the exact weight of a cut. The momme factor is a trade convention, so two sellers may round it differently in the last digit.
Assumptions and limits
- The ounce is the avoirdupois ounce (28.349523125 g) and the yard is 0.9144 m.
- One momme is converted at the common factor of 4.3056 g/m2, a convention used for silk.
- The width, when given, is the usable width of the fabric as sold.
- Weights are nominal and vary by mill, finish and washing.
Frequently asked questions
How do I convert GSM to ounces per square yard?
Divide grams per square meter by 33.9057. For example, 339 GSM is about 10 oz/yd2. To go the other way multiply ounces per square yard by 33.9057.
What does a momme number mean?
It is a silk weight. A higher momme number means a heavier, denser silk, and the number converts to grams per square meter at 4.3056. A silk sold as 16 momme weighs about 69 g/m2.
Why enter a width?
The weight of a length of cloth depends on how wide it is. With the width, the page can tell you what a linear yard or meter weighs, which helps with shipping or comparing roll prices.
Are ounces per linear yard the same as ounces per square yard?
No. Per square yard measures the area. Per linear yard measures a strip the full width of the bolt. They differ by the width in yards, so a 58 inch fabric weighs 1.611 times its square-yard weight per linear yard.