Calculating Paper weights

Calculate the surface area of the job in millimetres.
Divide by 1 million.
Multiply by the paper weight

Example

a 4pp A4 leaflet on 130 gsm paper

297 x 420 = 124,740

124,740 / 1,000,000 = 0.12474

0.124,740 * 130 = 16.2162 gsm or just over 16 gsm!!!

Frank