Tool
Paper weight converter
gsm to pounds and back — correctly, which means asking which grade you mean. There is no single lb-to-gsm factor: 80 lb Text is 118 gsm, 80 lb Cover is 216 gsm, because each grade is weighed on a different basis sheet.
Grammage
118
gsm (g/m²)
Basis weight · Text
80
lb, on 25 × 38 in
Noticeably substantial letterhead and quality flyers. Little show-through.
One A4 sheet
7.39 g
1 sheet
7.4 g
Ream (500)
3.69 kg
The same “80 lb” in every grade
Why the grade is not an optional detail.
- Bond / Writing / Ledger301 gsm
- Text / Book / Offset118 gsm
- Cover216 gsm
- Bristol175 gsm
- Index145 gsm
- Tag130 gsm
- Newsprint130 gsm
Where the pound figure comes from
Take 500 sheets of paper at the size the mill cuts that grade to, put them on a scale, and the reading in pounds is the basis weight. It is a genuinely practical measure for a mill selling by the ream — and a confusing one for everyone downstream, because the basis size is different for each grade and never appears on the label.
Grammage sidesteps the problem entirely: grams per square metre is the same question asked the same way of every paper on earth. When a printer quotes gsm you know exactly what you are getting; when they quote pounds you need to know the grade before the number means anything. That is the whole reason the table above exists.
Weight is not thickness, either. Thickness is measured separately, in mils or microns, and is not derivable from weight: two sheets at the same gsm differ in caliper depending on how much the stock was compressed. A bulky uncoated sheet feels thicker than a coated one of identical grammage. If a project depends on stiffness rather than substance, ask for caliper in microns and treat gsm as a rough proxy. For the sizes themselves, the paper size chart covers all 48 standards.
Frequently asked questions
Why can I not just multiply pounds by a single number?
Because the pound figure is not a weight per area — it is the weight of 500 sheets cut to that grade’s own basis size, and every grade uses a different basis size. Text paper is weighed at 25 × 38 inches, Cover at 20 × 26. So 80 lb Text is 118 gsm and 80 lb Cover is 216 gsm: the same number describing sheets of nearly double the substance. A converter with one conversion factor is right for one grade and wrong for the rest.
What is 80 gsm paper?
Standard European office and copier paper. Its closest US equivalent is 20 lb Bond, which works out at 75 gsm — so a ream of American copier paper is very slightly lighter than a European one, which is occasionally enough to matter in a sheet-feeder calibrated for one or the other.
What weight should I use for flyers and business cards?
Flyers work from about 130 gsm, where the sheet stops feeling like a photocopy, up to roughly 170 gsm for something that survives handling. Business cards start around 300 gsm and premium cards run 350–400 gsm. Below 250 gsm a card feels flimsy in the hand no matter how well it is printed — substance is most of the perceived quality.
Does higher gsm mean thicker paper?
Thickness is measured separately, in mils or microns, and is not derivable from weight: two sheets at the same gsm differ in caliper depending on how much the stock was compressed. A bulky uncoated sheet feels thicker than a coated one of identical grammage.
What weight can my home printer handle?
Most inkjet and laser printers manage up to about 200 gsm through the main tray, and some reach 250–300 gsm through a rear or manual feed that keeps the paper path straight. Above that, home equipment generally cannot pull the sheet reliably. Check the specification before buying card stock — a jam on 300 gsm through a curved paper path is a mechanical limit, not a setting.
How do I work out what a mailing will weigh?
Multiply grammage by sheet area in square metres, which the calculator above does for any standard size: an A4 sheet at 80 gsm is 5 grams, so ten sheets and an envelope stay inside a 100 g postal band comfortably. Weight bands are where paper choice quietly becomes a cost decision — moving a mailer from 100 gsm to 120 gsm can push a whole campaign into the next tier.