The area density (also known as areal density, surface density, superficial density, or density thickness) of a two-dimensional object is calculated as the mass per unit area. The area density is often used to describe the thickness of paper, carton, fabric, etc.
The SI derived unit for area density is kilograms per square meter (or grams per square meter).
For example, typical values of cotton density used for shirts are 60-100 g/m2, for jeans - 400 g/m2
Running, or linear meter, is term often used in fabric manufacturing. For roll of fabric the width of roll is usually known.
Hence, the mass, the length, the width and the area density of the roll are related according to the following formula:
If you know any three, it is easy to find the unknown, thus, calculator below can find: