Use a known measured width for GSM and linear-weight conversion. For area mass, explicitly choose total or usable width. Calculations do not estimate thickness, warmth, garment consumption or packaging.
If the answer looks plausible but the source is incomplete
Keep the result provisional when the original unit or width basis is unclear. Copy the source statement into your own project record and ask for its meaning before using the conversion in a purchasing decision. Arithmetic validates a calculation under entered assumptions; it cannot validate the identity or measurement basis of the fabric.
A conversion result disagrees with a label
Check the original unit and the width corresponding to that weight before recalculating. Preserve the supplied value beside the output. Replacing total width with usable width changes the area basis, so it can change a linear-mass conversion without establishing that the supplier's cloth is out of specification.
If the mismatch remains, ask which current statement applies to the identified sample and what evidence supports it. Do not average the two figures or turn a calculator result into a test report. The tool checks entered arithmetic; the project still needs the correct sample identity, measurement basis and agreed requirement.
Check the arithmetic
500 GSM × 1.5 m = 750 g/linear m. 750 g/linear m ÷ 1.5 m = 500 GSM. 500 GSM × 1.5 m × 1000 m ÷ 1000 = 750 kg for the entered total fabric area, excluding packaging. These examples are arithmetic, not product specifications.
1 yd = 0.9144 m; 1 in = 0.0254 m. The width must correspond to the material described by the weight value.