Determine the weight in grams per square meter (gsm) for a ream of paper of a given basic size and grade based on its basis weight in pounds. When filling in the basis weight field, use either a whole number or a decimal fraction.

For a table of select standard paper weights given in both pounds and grams, see our Equivalent Weights & Grammage Conversion Chart.

Basis Weight to Grammage Calculator
Basis Weight: lbs.
Select… (Or type in values below.)
Basic Size:(length × width) length
Grams per
Square Meter =

The numerical results from this calculator are estimates only and are not guaranteed.


Find the weight in grams per square meter (gsm) for a ream of 25″ × 38″ book paper that has a basis weight of 45 lbs.


 Basis Weight × 1406.5

Basic Size

= Grams per square meter (gsm)


 45 × 1406.5

(25 × 38)

= 67 gsm (66.62 rounded to the nearest whole number)


See also…

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