Standard circular sample
100 cm² cutter
A 100 cm² swatch has an area of 0.01 m². Multiply its mass in grams by 100 to calculate grams per square meter.
GSM = swatch weight (g) × 100
Textile specification utility
Fabric GSM calculator
Calculate areal density from a weighed swatch, convert between metric and imperial fabric weight, or estimate linear mass from usable roll width.
Use the result for
- Comparing a sample with an approved fabric specification.
- Keeping GSM and oz/yd² values consistent between teams.
- Estimating grams per running meter from a cuttable width.
Enter measured values
Choose the calculation that matches your sample
Use a calibrated scale and accurately cut or measured swatch. Fields begin empty so the displayed result always comes from the values you provide.
Measured input
Standard cutter sample
Measure the sample cleanly and use a scale with suitable precision. A blank or invalid measurement does not produce an estimate.
Calculation method
The units stay visible
Measured rectangle
Any measured area
Convert length and width from millimeters to meters, multiply for area, then divide the swatch mass by that area.
Area = (length mm ÷ 1000) × (width mm ÷ 1000)
GSM = weight (g) ÷ area (m²)
Unit conversion
Metric and imperial
Use a conversion constant of 33.906 for GSM and ounces per square yard.
oz/yd² = GSM ÷ 33.906
GSM = oz/yd² × 33.906
Linear fabric mass
Running meter
Use the cuttable width in centimeters, measured inside the selvedges, to estimate the fabric mass per linear meter.
g/m = GSM × (cuttable width cm ÷ 100)
Production planning
Use GSM as one input in the fabric decision
For broader production context, read the Bangladesh versus India manufacturing comparison.
Marker and consumption
Weight informs fabric planning alongside pattern area, usable width and marker layout. This calculator does not generate a marker or finished garment yield.
Shipment mass
Linear mass can support an estimate for a known fabric length and usable width. Garments, trims, packaging and carton tare are outside this swatch calculation.
Finishing changes
Dyeing, stenter framing, mechanical compacting and coatings can change finished GSM relative to greige fabric.
Condition the sample
Moisture regain can change measured mass. ISO 139 conditioning applies to formal laboratory testing; this tool does not condition the fabric.
Limits of the estimate
A calculation is not a lab report
Sample-edge fraying, moisture and scale accuracy affect the measured value. Cut cleanly and record the sample dimensions in the selected units.
Shrinkage and finishing can change density after the sample is measured. Use a conditioned, finished swatch for material approval where required.
Typical GSM tolerances depend on fiber blend and knit or woven construction. Confirm the acceptance range in the approved specification.
Next step
Review a fabric specification
Share the material target, sample measurements and planned garment use with the production team.