What is GSM?
GSM is short for grams per square meter. All fabrics have a weight, and the standard measurement for the weight and quality of fabrics (including towels) is grams per square meter. This number refers to the density of the towel. High quality towels are generally heavier and are more absorbent.
Towels can vary anywhere between 300 GSM and 900 GSM. The lower the number, the lighter and thinner the towel. For instance:
300-400 GSM – In this weight, as noted, the towels are lighter and thinner. But, depending on its use, you might want a lower GSM for the gym towel or a kitchen towel, or economy towel. A lightweight, quicker-drying beach towel might be around 350 GSM, for instance.
400-600 GSM – This is a medium weight. This weight is great for beach towels, bath towels, guest towels. Each consecutive gram weight –400, 500, 600– gets a little heavier, and a little more absorbent.
600-900 GSM – This is a premium, luxury weight. The towel will be denser, heavier, more absorbent. It will probably take a little longer to dry.
Other factors that will influence the towel’s softness and absorbency are: type of cotton, regular cotton or ringspun cotton. Or whether the manufacturer uses a polyester blend. whether the cotton is a single or double loop, 10s (10 Singles), or 16s (16 Singles).
Convert Weight per Dozen to GSM
The standard measurement for weight and quality of fabrics is grams per square meter (GSM). This is the accepted standard in the United States as well as in foreign countries. However, many towels in the US rated by weight per dozen. Towels and bath robes typically vary from 300 to 800 GSM; other fabrics may have values as low as 100 GSM. The reason grams per square meter are used even in the U.S. is that they are a more accurate indicator of quality than pounds.
Let’s compare, for example, two towels both weighing 18.0 lbs per dozen.
- Determine the lbs of the towel(s):
- In Pounds that is 18 lbs ÷ 12 (dozen) = 1.5 lbs per Towel, or
- Determine the grams of the towel(s):
- 1.5 lbs per towel x conversion factor of 453.59237 = 680.89 grams per towel
Towel A: weighs 1.5 pounds (680 grams) and measures 27” width by 54” length.
- Convert inches to meters by multiply the conversion factor by the inches
- 27” x .0254 (inches to meters conversion Factor) = .6858 meters
- 54” x .0254 (inches to meters conversion Factor) = 1.3716 meters
- Determine Total Surface Area in Square Meters by multiplying the length and width in meters.
- .6858 meters x 1.3716 meters = .941 square meters
- GSM will equal the grams ÷ the square meter
- 680 Grams ÷ .941 square meters = 723 GSM
Towel B: Also weighs 1.5 pounds (680 grams) but is larger and measures 30” length by 60” width.
- Convert inches to meters by multiply the conversion factor by the inches
- 30” x .0254 (inches to meters conversion Factor) = .7620 meters
- 60” x .0254 (inches to meters conversion Factor) = 1.5340 meters
- Determine Total Surface Area in Square Meters by multiplying the length and width in meters.
- .7620 meters x 1.5240 meters = 1.161 square meters
- GSM will equal the grams ÷ the square meter
- 680 Grams ÷ 1.161 square meters = 586 GSM
Towel B is only 586 GSM—nice but not nearly as plush as Towel A @ 723 GSM
As you can see from these examples, there is no direct conversion between GSM and pounds; the total weight of the towel is actually the product of the GSM and the towel’s dimensions.
Download the Automatic GSM Towel Calculator