How do you calculate to gsm of paperboard?

To calculate the grams per square meter (gsm) of paperboard, you first need to weigh a sample of the paperboard in grams. Then, measure its dimensions in meters (length and width). The gsm can be calculated using the formula: ( \text{gsm} = \frac{\text{weight (g)}}{\text{area (m}^2\text{)}} ). For example, if you have a piece weighing 200 grams and measuring 1m x 1m, the gsm would be 200 g/m².