A GSM calculator finds the grams per square meter of paper, fabric, cloth, cardboard or film from the weight and size of a sample. Use it to check material weight, quality and thickness quickly and accurately.
A standard 100 cm² cutter is 11.28 cm across.
GSM stands for grams per square meter. It tells you how much one square meter of a material weighs. A paper or fabric rated at 80 GSM weighs 80 grams for every square meter, and one rated at 400 GSM weighs 400 grams for the same area.
GSM is the standard way to compare the weight of paper, cardboard, fabric, non-woven material and film. A higher GSM usually means a thicker, heavier and sturdier material. A lower GSM means a lighter, thinner and more flexible one.
When people search for “GSM cloth” or “GSM of cloth”, they mean the weight of one square meter of cloth in grams. It is the main number used to describe how light or heavy a cloth is. A 150 GSM cloth is light and airy, while a 400 GSM cloth is thick and heavy.
In the textile industry, GSM is the standard measure of fabric weight (also called textile GSM). Mills, garment makers, exporters and buyers use it to specify, price and compare fabric. You will find it on fabric specifications, order sheets and quality reports, next to the fiber content, yarn count and fabric width. Textile GSM applies to woven, knitted and non-woven fabrics alike.
GSM measures weight, not quality. Two fabrics with the same GSM can feel different depending on the fiber, yarn and weave.
GSM is worked out from the weight of a sample and the area of that sample:
GSM = (Weight in grams × 10,000) ÷ (Length × Width in cm)
Example 1 (paper): A 10 cm × 10 cm piece of paper weighs 0.8 g.
GSM = (0.8 × 10,000) ÷ (10 × 10) = 8,000 ÷ 100 = 80 GSM
Example 2 (fabric): A 10 cm × 10 cm swatch of cloth weighs 4 g.
GSM = (4 × 10,000) ÷ (10 × 10) = 40,000 ÷ 100 = 400 GSM
Quick shortcut: A 10 cm × 10 cm sample has an area of exactly 100 cm², which is 1/100 of a square meter. So you can simply multiply its weight in grams by 100. A sample that weighs 2 g is 200 GSM, and one that weighs 5 g is 500 GSM.
A GSM calculator is an online tool that finds the grams per square meter of a material from the weight and size of a small sample. You do not need to convert units or work out the area by hand. You enter the measurements, and the calculator applies the GSM formula and gives you the result instantly.
It works for paper, cardboard, fabric, cloth and other textile materials (woven, knitted and non-woven), plastic film and any other flat material you can cut and weigh.
To find the GSM of cloth or any textile, cut a 10 cm × 10 cm swatch, weigh it in grams and enter the size and weight above. As a quick check, multiply the weight in grams by 100.
Tip: Check the size unit before you calculate. The same numbers give very different answers in centimeters and in meters. A 10 × 10 sample weighing 0.8 g is 80 GSM in centimeters but only 0.008 GSM in meters.
For the best accuracy, cut and weigh two or three samples from different parts of the roll or sheet and take the average.
Woven fabric is made by interlacing two sets of yarn at right angles: the warp (lengthwise) and the weft (crosswise). Shirting, denim, twill, canvas, poplin and upholstery cloth are all woven fabrics.
A GSM calculator for woven fabric uses the same formula, applied to a swatch of the cloth. For woven fabric, GSM is closely linked to the yarn count, the number of threads per inch and the weave type. That is why it is one of the first numbers a buyer, tailor or textile mill checks.
When you test woven fabric:
One of the most common questions is what a given GSM means in cloth, such as 200 GSM cloth, 400 GSM cloth or 500 GSM fabric. The table below gives the typical use of each range. The ranges are approximate and vary by fiber, weave and finish.
| GSM | Weight class | Typical use |
|---|---|---|
| Under 100 | Very light | Chiffon, voile, georgette, linings |
| 100 – 150 | Light | Summer shirts, blouses, lawn, light poplin |
| 150 – 200 | Light to medium | T-shirts, polo shirts, light twill, bedsheets |
| 200 GSM | Medium | Standard T-shirts, trousers, kurtas, regular cotton fabric |
| 250 – 300 | Medium to heavy | Premium T-shirts, light hoodies, light jeans, curtains |
| 300 – 400 | Heavy | Sweatshirts, hoodies, denim, workwear, jackets |
| 400 GSM | Heavy | Thick hoodies and fleece, heavy denim, uniforms, light upholstery |
| 500 GSM and above | Very heavy | Canvas, upholstery, heavy jackets, sofa fabric, bags, tarpaulin |
200 GSM is a mid-weight fabric. It is the usual choice for good-quality T-shirts and everyday cotton clothing. It feels solid but is still comfortable in warm weather.
300 GSM is a heavy cloth used for hoodies, sweatshirts, light denim and curtains. It gives warmth and structure.
400 GSM is thick and heavy. It is common in winter hoodies, fleece, heavy denim, uniforms and light upholstery. It holds its shape well and is warm, but it is too heavy for summer clothing.
500 GSM is very heavy and stiff. It is used for canvas, upholstery, sofa covers, bags and heavy-duty jackets, where strength matters more than softness.
| GSM | Typical use |
|---|---|
| 60 – 90 | Newsprint, notebooks, copier and office paper (75 to 80 GSM is standard) |
| 100 – 130 | Letterheads, brochures, magazine pages |
| 130 – 170 | Flyers, posters, leaflets |
| 200 – 300 | Postcards, book covers, high-quality cards |
| 300 – 400 | Business cards, invitations, folders, light packaging |
| 400 and above | Cardboard, boxes, rigid packaging |
Some fabrics, especially denim, are sold in ounces per square yard (oz/yd²). To convert, divide GSM by 33.9. For example, 400 GSM is about 11.8 oz/yd², and 200 GSM is about 5.9 oz/yd². To go the other way, multiply oz/yd² by 33.9.