Weight formula
The calculator converts square feet to square meters, multiplies area by grams per square meter (GSM), then converts grams to kilograms and avoirdupois pounds. If you enter ounces per square yard, that fabric weight is first converted to GSM.
What the estimate includes
The result estimates the sheet or fabric mass. Finished weight may be higher because of hems, rope reinforcement, grommets, seams, patches, labels, coatings, and moisture.
Worked example
A 16 × 20 ft tarp has an area of 320 sq ft, or about 29.73 m². At 180 GSM, the material estimate is about 5.35 kg or 11.8 lb before hardware and finishing.
GSM is fabric mass, not a complete durability rating
A higher GSM usually means more material per unit area, but it does not reveal fiber quality, weave or scrim construction, coating chemistry, UV stabilization, seam strength, or grommet reinforcement. Compare the full finished specification when durability matters.
Conversion basis: NIST unit conversion guidance and exact avoirdupois mass and yard definitions. Calculations keep full precision and round only the displayed result.