GSM to Oz/yd² Converter
| Item | GSM | oz/yd² | Note |
|---|---|---|---|
| Printer paper | 80 | 2.4 | the office standard |
| Light t-shirt jersey | 150 | 4.4 | printed blanks |
| Standard t-shirt | 180 | 5.3 | everyday weight |
| Hoodie fleece | 320 | 9.4 | warmth layer |
| Denim | 400 | 11.8 | jeans territory |
| Heavy canvas | 500 | 14.7 | tote bags, workwear |
Fabric weight speaks two dialects: the metric world weighs a square meter - GSM, grams per square meter - and the American trade weighs a square yard in ounces. The bridge is one factor: 1 oz/yd² equals 33.906 GSM. A 180 GSM t-shirt is a 5.3 oz tee; 400 GSM denim is 11.8 oz denim, the weight of jeans that outlive their owner. Type either number and the converter lands the other.
Weight is the honest quality signal in fabric and paper alike: heavier means more fiber per area, which usually means drape, durability and price move together. The anchors make the scale real - printer paper is 80 GSM, a standard tee 150-180, a proper hoodie 300-400, denim 400 and up - and the table carries the everyday weights so a supplier's quote stops being a guessing game.
How to use
- Type the GSM from a fabric listing or the oz/yd² from an American supplier - the other unit appears instantly.
- Match the table: tees live at 150-180 GSM, hoodies 300-400, denim 400+, printer paper at 80.
- Buying by weight? Heavier costs more to ship too - the same factor prices the freight, not just the fabric.
Frequently asked questions
What does GSM mean in fabric?
Grams per square meter - the weight of one square meter of the fabric, measured on a standard-sized swatch. It is the metric world's fabric density: higher GSM means more fiber per area, which tracks with thickness, warmth, drape and durability. The same term runs paper (80 GSM printer paper) and every fabric from chiffon at 30 GSM to canvas past 500.
How do I convert GSM to ounces per square yard?
Divide GSM by 33.906 - or multiply oz/yd² by 33.906 to go the other way. The factor falls out of the units: an ounce is 28.35 grams, a square yard is 0.836 square meters, and 28.35 divided by 0.836 lands at 33.9 grams per square meter per ounce. No approximations, no garment-industry folklore - it is the yard and the ounce speaking their exact definitions.
What GSM is a good t-shirt?
150-180 GSM is the standard tee: light, breathable, the blank most printed shirts use. 180-200 GSM reads as heavyweight - the boxy premium tee that holds its shape past a hundred washes. Past 200 GSM you are in sweatshirt territory. Heavier also means slower drying and warmer wear, so the right number depends on whether the shirt is for August or October.
Why do denim ounces feel so much heavier than shirt ounces?
Because denim is quoted in the same oz/yd² as shirting but lives at four times the weight: 10-12 oz is standard jean denim, 14-16 oz is the raw selvedge that stands up on its own, and 21 oz is the Japanese specialty weight that could nearly stand alone. The units are identical - only the fabric changes. A 12 oz jean leg and four 3-oz blouses weigh the same per area; only one survives a decade.
Is paper GSM the same system as fabric GSM?
Exactly the same - grams per square meter, no conversion needed between them. That is why 80 GSM printer paper and 80 GSM fabric weigh the same per area while feeling nothing alike: density differs, the weight measurement does not. Printers, cardstock and fabric suppliers all quote the same metric, which makes this converter work for paper weights too - oz/yd² is just rarer in the paper trade.