Paper weight and gsm explained
Paper weight is given in grams per square metre, written g/m² or gsm. Ordinary copy paper is 80 g/m². Because an A4 sheet is one sixteenth of a square metre, it weighs just under 5 grams.
Contents of this page
What g/m² means
Grammage tells you how much one square metre of the paper weighs. It is measured according to ISO 536. Since an A0 sheet has an area of exactly one square metre, there is an easy way to remember it: the grammage is the weight of an A0 sheet. An A0 sheet of copy paper weighs 80 g, an A1 sheet 40 g, an A4 sheet 5 g.
Grammage says nothing about thickness. A bulky uncoated paper at 100 g/m² can be thicker than a smooth coated paper at 135 g/m². Thickness depends on the paper’s bulk (also called volume), which paper makers list in their data sheets.
Which weight for what?
| Weight | Typical use |
|---|---|
| 60 to 70 g/m² | bible paper, carbonless forms, notepads |
| 80 g/m² | copy paper, printouts, exercise books |
| 90 to 100 g/m² | letterheads, job applications, quality printouts |
| 115 to 135 g/m² | flyers, inside pages of brochures, posters |
| 150 to 170 g/m² | premium flyers, folded leaflets, posters |
| 200 to 250 g/m² | brochure covers, invitations, folders |
| 300 to 350 g/m² | postcards, business cards, folded cards |
| 400 g/m² and more | very stiff business cards, swing tags, packaging |
Weight per sheet for every A size
| Size | 80 g/m² | 100 g/m² | 170 g/m² | 300 g/m² |
|---|---|---|---|---|
| A0 | 80 g | 100 g | 170 g | 300 g |
| A1 | 40 g | 50 g | 84.9 g | 149.9 g |
| A2 | 20 g | 24.9 g | 42.4 g | 74.8 g |
| A3 | 9.98 g | 12.5 g | 21.2 g | 37.4 g |
| A4 | 4.99 g | 6.24 g | 10.6 g | 18.7 g |
| A5 | 2.49 g | 3.11 g | 5.28 g | 9.32 g |
| A6 | 1.24 g | 1.55 g | 2.64 g | 4.66 g |
| A7 | 0.62 g | 0.78 g | 1.32 g | 2.33 g |
A ream of 500 sheets of 80 g/m² A4 therefore weighs just under 2.5 kg. If you need to post a whole print job, these figures give you a quick estimate of the shipping weight. The paper weight calculator does the sum including the envelope and shows the matching German letter type.
Paper, card or board?
The German standard DIN 6730 defines the terms, but in practice the boundaries are fluid. As a rule of thumb, up to about 150 g/m² is paper, between about 150 and 600 g/m² is card (or cardstock), and above that is board. A letterhead is paper, a postcard is card, and a file cover made of grey board is board.
US paper weights in pounds
In the US, paper is described in pounds (lb): the weight of 500 sheets in a basic size that differs from one paper category to another. That is why the numbers cannot be compared directly, and why 80 lb text is much thinner than 80 lb cover. Some reference points:
| US weight | About |
|---|---|
| 20 lb Bond | 75 g/m² |
| 24 lb Bond | 90 g/m² |
| 28 lb Bond | 105 g/m² |
| 80 lb Text | 118 g/m² |
| 100 lb Text | 148 g/m² |
| 80 lb Cover | 216 g/m² |
| 100 lb Cover | 270 g/m² |
Paper weight and postage
With letters, a single sheet often decides the postage. A Deutsche Post Standardbrief may weigh 20 g. With 80 g/m² paper, two A4 sheets fit safely into a DL envelope, and the third makes it tight. On 100 g/m² letterhead you are close to the limit with only two sheets. Royal Mail is more generous: a Letter may weigh up to 100 g. All German weight bands are on German letter sizes.
Frequently asked questions
How much does an A4 sheet weigh?
At 80 g/m², an A4 sheet weighs 4.99 grams. At 100 g/m², 6.24 grams.
What does 80 gsm mean?
One square metre of the paper weighs 80 grams. That is the weight of an A0 sheet.
How much do 500 sheets of A4 weigh?
At 80 g/m², about 2.5 kilograms.
When does paper become card?
As a rule of thumb from about 150 g/m². From about 600 g/m² it is called board.
What is 20 lb paper in gsm?
20 lb bond is about 75 g/m², the standard US copy paper.