Find out what the weight number measures
A fabric weight without a unit is incomplete. Grams per square metre measure mass per area; grams per linear metre measure mass along a length at a specified width. A supplier may also use another original unit. Record it exactly before converting.
Ask whether the value is a target or a measured figure and which finished article it describes. A reference swatch, an unconfirmed product listing and a report may use different bases. Do not treat a bare “280” as 280 g/m² because that is the unit you expected.
Distinguish total width from usable width
Total width can include edges that the cutting team cannot use. Usable width is the width available under the agreed cutting basis. Ask how edges are handled and whether the stated width applies after finishing. The answer should identify the actual article and condition.
Use usable width for a cutting discussion. If two quotes use different width definitions, clarify them before comparing area or consumption. A total width copied into a usable-width field can make an offer appear better than the material actually supplied.
Understand the area-to-length weight relationship
For a uniform fabric at a stated width, grams per linear metre can be estimated by multiplying grams per square metre by width in metres. For example, 280 g/m² × 1.50 m gives 420 g per linear metre on that width basis. This is dimensional arithmetic, not an inspection result.
Use the width that matches the purpose of the calculation. Total and usable widths can produce different area bases. Do not infer a billed kilogram-to-metre quantity from this estimate unless the supplier confirms the actual measurement and commercial basis, including how relevant edges or allowances are handled.
Keep metre and yard conversions exact
One yard equals 0.9144 metre. Multiply yards by 0.9144 to express length in metres; divide metres by 0.9144 to express length in yards. For a unit price, the operation reverses with the denominator: price per yard divided by 0.9144 gives price per metre.
Round only for the stated purpose and retain the original value. The quote comparison tool supports explicit length-unit conversion but does not make different currencies or kilogram and metre offers equivalent. A correct conversion cannot repair a different fabric specification.
Illustrative diagnosis: equal GSM, different metre weight
Two sample descriptions both state 280 g/m². One is based on 1.50 m width and the other on 1.40 m. On those respective area bases, their estimated mass per linear metre is 420 g and 392 g. Equal GSM does not require equal grams per metre.
The buyer then checks which widths are usable and which calculation is relevant to the question. It avoids accusing a supplier of inconsistency merely because different units give different numbers. The example uses illustrative specifications and does not establish a supplied fabric or allowable tolerance.
Send a unit clarification rather than a guess
Ask the supplier to return the original unit, width definition and measurement context together. If a weight or width range matters, agree how it is evaluated and what requirement applies; do not invent a general industry tolerance.
Keep calculations labelled as calculations and supplier measurements labelled by their source. This helps a cutting team, merchandiser and buyer discuss the same basis without converting an estimate into confirmed stock or billable quantity.
Article / specification revision: Quoted weight value and original unit: Target or measured; sample/finished basis: Total width: Usable width and excluded edges: Width used for any g/m calculation: Original length and price units: Conversion purpose and formula: Please clarify the missing unit/width basis before we compare consumption or price.
Fabric unit questions
Are GSM and grams per metre the same?
No. GSM is mass per square metre. Grams per linear metre depend on fabric width as well as area mass.
Can I calculate kilogram pricing using GSM alone?
GSM alone is insufficient. Confirm width and the supplier’s actual commercial measurement basis before converting billed weight and length.
What if the usable width is still unknown?
Keep consumption and width-dependent comparisons provisional. Request the cutting-width basis for the selected finished article instead of using a familiar standard width.