Fabric Weight Calculator
What a cut of fabric actually weighs.
Calculate the weight of a length of fabric from its dimensions and GSM, for shipping costs and postage bands.
Shipping weight
1.50 kg
7.50 m² of fabric
Couriers charge on the greater of actual and volumetric weight, and a roll of fabric is bulky for its mass. Check the chargeable weight calculator before quoting postage — a light bolt on a long tube is usually billed on volume.
How the Fabric Weight Calculator works
Fabric weight is charged by couriers and quoted by mills in units that sound small, which is why a bolt routinely costs more to post than the sender expected. A GSM figure multiplied out over a few metres of a wide bolt adds up quickly, and it is the number that decides which postage band an order falls into.
Also known as: fabric shipping weight calculator · bolt weight calculator
How the number is derived
Weight is areal density times area. Multiply length by width in metres for the area, then by the GSM for the mass in grams. Five metres of 1.5 metre fabric at 200 gsm is 7.5 square metres and 1,500 grams.
The figure people underestimate is how quickly this accumulates. GSM sounds small because it is per square metre, and a bolt contains a lot of square metres — a full 15 yard bolt of 340 gsm denim at 60 inches wide is close to 7 kilograms.
For shipping, add the tube and packaging. A cardboard tube is a few hundred grams but, more importantly, fixes the parcel's dimensions.
A worked example
Three metres of 1.4 metre quilting cotton at 140 gsm: 4.2 square metres, 588 grams. Add a 250 gram tube and the parcel is 838 grams — comfortably inside a one kilogram postage band.
The same three metres of 340 gsm denim at 1.5 metres wide is 1,530 grams before packaging, which lands in a different band entirely. Fabric weight is frequently what decides whether an order is profitable to post.
Where the answer misleads
Couriers charge on the greater of actual and volumetric weight, and rolled fabric is bulky for its mass. A light bolt on a long tube is very often billed on volume rather than on the number this calculator produces — check the chargeable weight before quoting postage.
Fabric also absorbs moisture. Natural fibres can carry several percent of their weight in water depending on humidity, which is enough to move a borderline parcel into the next band on a damp day.
Finally, the GSM on a spec sheet is nominal and has a tolerance, usually a few percent either way. For a single cut that is irrelevant; across a container of fabric it is not.
Frequently asked questions
How do I work out the weight of a length of fabric?
Multiply the length in metres by the width in metres to get the area, then multiply by the GSM. That gives grams. Five metres of 1.5 metre fabric at 200 gsm is 7.5 square metres and 1.5 kilograms.
Does the roll or tube count?
For shipping, yes. A cardboard tube adds a few hundred grams and, more importantly, sets the parcel's dimensions, which often makes the dimensional weight rather than the actual weight the billable figure.
Which weight do carriers charge on?
The greater of actual and volumetric weight. A roll of light fabric is bulky for its mass, so it is frequently billed on volume — worth checking with a chargeable weight calculator before quoting postage.
How heavy is a typical bolt?
A full bolt of quilting cotton, around 15 yards at 44 inches and 140 gsm, is roughly 2.5 kilograms. The same length of 340 gsm denim at 60 inches is closer to 8.