Paper weight converter
Type a paper weight and convert between metric g/m² and the US basis weight in pounds for each paper grade. US pounds are the weight of 500 sheets of the grade's basic size, so the same pound number means different papers.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Type a number. A dot or a comma works as the decimal separator.
- Choose the unit you have and the unit you need. The ⇄ button swaps them.
- The table shows the same paper weight in g/m² and for every US grade.
How it works
US basis weight is the weight in pounds of 500 sheets of the grade’s basic size. Dividing the pound (453.59237 g) by the area of those 500 sheets gives the GSM per pound.
| Grade |
Basic size (in) |
GSM per lb |
| Bond |
17 × 22 |
3.7597 |
| Text / book |
25 × 38 |
1.4801 |
| Cover |
20 × 26 |
2.7041 |
| Index |
25.5 × 30.5 |
1.8080 |
| Bristol |
22.5 × 28.5 |
2.1928 |
Worked example
Standard office paper is 20 lb bond: 20 × 3.7597 = 75.2 g/m². A 100 lb cover stock is 100 × 2.7041 = 270 g/m². Going the other way, 20 lb bond equals 20 × 950 ÷ 374 = 50.8 lb text.
Tips
- Always say which grade a pound weight refers to.
- Some mills name grades differently (for example, “offset” for text), and a few use other basic sizes; check the supplier’s sheet for borderline cases.
Frequently asked questions
How many GSM is 20 lb bond paper?
About 75.2 g/m². Bond paper is rated on a 17 × 22 in sheet, so 20 lb bond is 20 × 3.7597 g/m² per pound.
Why is 80 lb cover so much heavier than 80 lb text?
The pound number is the weight of 500 sheets of the grade's own basic sheet. Cover uses 20 × 26 in and text uses 25 × 38 in, so one pound of cover is 2.704 g/m² and one pound of text is 1.480 g/m². 80 lb cover is about 216 g/m²; 80 lb text is about 118 g/m².
How is the conversion calculated?
GSM per pound = 453.59237 g ÷ (500 sheets × sheet area in m²), with the sheet area from inches × 0.0254. It is computed, not read from a table, so the figures can differ slightly from rounded printers' charts.
Does the converter cover A4 and other ISO paper?
ISO paper is sold directly in g/m², so no conversion is needed. This tool only converts g/m² to and from the US pound weights. For sheet dimensions use the paper size converter.