GSM and grams per metre are different.
GSM measures mass per unit area: grams per square metre. A running metre is one metre of length across the full stated width. Two fabrics with the same GSM can have different grams per running metre if their widths differ.
Width in metres = width in inches × 0.0254
Grams per running metre = GSM × width in metres
GSM = grams per running metre ÷ width in metres
Metres per kilogram = 1,000 ÷ grams per running metre
A worked example at 58 inches
At 200 GSM and 58 inches (1.4732 metres) wide, one running metre weighs 294.64 grams. One kilogram corresponds to approximately 3.394 metres. This is an illustrative calculation, not the measured GSM of an Anirudh quality.
Use a consistent measurement basis.
Enter the width used for the weight measurement. Do not mix total width with usable cutting width. Use net fabric mass, excluding tubes and packaging. Real roll yield also depends on measured weight variation, usable length and cutting losses; this calculator does not estimate those losses.
For test-based procurement, specify the measurement method, conditioning and acceptance tolerances with your supplier or laboratory. ASTM D3776/D3776M is a reference standard for fabric mass per unit area. The calculator is a unit conversion, not a laboratory test.
Record the result alongside your fabric specification, then ask our team about the selected quality.