Paper
Paper Weight Chart: GSM to lb Conversion
Why a “20 lb” sheet and a “50 lb” sheet can be the same paper — and what grammage to choose for book interiors and covers.
GSM to pounds
| GSM | Bond lb | Text lb | Cover lb | Index lb | Typical use |
|---|---|---|---|---|---|
| 35 g/m² | 9.3 | 23.6 | 12.9 | 19.4 | Bible / India paper, dictionaries, pharmaceutical inserts |
| 40 g/m² | 10.6 | 27 | 14.8 | 22.1 | Bible / India paper, dictionaries, pharmaceutical inserts |
| 45 g/m² | 12 | 30.4 | 16.6 | 24.9 | Newsprint, paperback novels, directories |
| 50 g/m² | 13.3 | 33.8 | 18.5 | 27.7 | Newsprint, paperback novels, directories |
| 55 g/m² | 14.6 | 37.2 | 20.3 | 30.4 | Book interiors (lightweight), notebooks, forms |
| 60 g/m² | 16 | 40.5 | 22.2 | 33.2 | Book interiors (lightweight), notebooks, forms |
| 64 g/m² | 17 | 43.2 | 23.7 | 35.4 | Book interiors (lightweight), notebooks, forms |
| 70 g/m² | 18.6 | 47.3 | 25.9 | 38.7 | Office copy paper, book interiors, letters |
| 75 g/m² | 19.9 | 50.7 | 27.7 | 41.5 | Office copy paper, book interiors, letters |
| 80 g/m² | 21.3 | 54 | 29.6 | 44.2 | Office copy paper, book interiors, letters |
| 90 g/m² | 23.9 | 60.8 | 33.3 | 49.8 | Premium book text, letterhead, colour interiors |
| 100 g/m² | 26.6 | 67.6 | 37 | 55.3 | Premium book text, letterhead, colour interiors |
| 105 g/m² | 27.9 | 70.9 | 38.8 | 58.1 | Flyers, brochures, premium letterhead, art-book interiors |
| 110 g/m² | 29.3 | 74.3 | 40.7 | 60.8 | Flyers, brochures, premium letterhead, art-book interiors |
| 115 g/m² | 30.6 | 77.7 | 42.5 | 63.6 | Flyers, brochures, premium letterhead, art-book interiors |
| 120 g/m² | 31.9 | 81.1 | 44.4 | 66.4 | Flyers, brochures, premium letterhead, art-book interiors |
| 130 g/m² | 34.6 | 87.8 | 48.1 | 71.9 | Flyers, brochures, premium letterhead, art-book interiors |
| 135 g/m² | 35.9 | 91.2 | 49.9 | 74.7 | Posters, brochure covers, photo books, art prints |
| 150 g/m² | 39.9 | 101.3 | 55.5 | 83 | Posters, brochure covers, photo books, art prints |
| 157 g/m² | 41.8 | 106.1 | 58.1 | 86.8 | Posters, brochure covers, photo books, art prints |
| 170 g/m² | 45.2 | 114.9 | 62.9 | 94 | Posters, brochure covers, photo books, art prints |
| 200 g/m² | 53.2 | 135.1 | 74 | 110.6 | Paperback covers, postcards, greeting cards, folders |
| 216 g/m² | 57.5 | 145.9 | 79.9 | 119.5 | Paperback covers, postcards, greeting cards, folders |
| 230 g/m² | 61.2 | 155.4 | 85.1 | 127.2 | Paperback covers, postcards, greeting cards, folders |
| 250 g/m² | 66.5 | 168.9 | 92.5 | 138.3 | Paperback covers, postcards, greeting cards, folders |
| 270 g/m² | 71.8 | 182.4 | 99.8 | 149.3 | Business cards, premium covers, invitations |
| 280 g/m² | 74.5 | 189.2 | 103.5 | 154.9 | Business cards, premium covers, invitations |
| 300 g/m² | 79.8 | 202.7 | 110.9 | 165.9 | Business cards, premium covers, invitations |
| 350 g/m² | 93.1 | 236.5 | 129.4 | 193.6 | Luxury business cards, packaging, rigid tags |
| 400 g/m² | 106.4 | 270.2 | 147.9 | 221.2 | Luxury business cards, packaging, rigid tags |
| 450 g/m² | 119.7 | 304 | 166.4 | 248.9 | Luxury business cards, packaging, rigid tags |
Basis sizes behind US paper weights
| Grade | Basic sheet | g/m² per lb | Used for |
|---|---|---|---|
| Bond / Writing | 17 x 22 in | 3.7597 | Office and writing papers: letterhead, copy paper, forms. |
| Text / Book / Offset | 25 x 38 in | 1.4801 | Book pages, brochures, flyers and offset printing papers. |
| Cover | 20 x 26 in | 2.7041 | Heavy stock for book covers, postcards, business cards and folders. |
| Index | 25.5 x 30.5 in | 1.808 | Stiff, smooth card for index cards, tabs and dividers. |
| Bristol | 22.5 x 28.5 in | 2.1928 | Thick drawing and printing board for illustration and tags. |
| Newsprint / Tag | 24 x 36 in | 1.6275 | Newspapers (newsprint) and tags. |
gsm = lb × 1406.14 ÷ (basic sheet area in square inches).
Pound weights by grade
- 16 lb bond 6 g/m²
- 20 lb bond 75 g/m²
- 24 lb bond 9 g/m²
- 28 lb bond 105 g/m²
- 32 lb bond 12 g/m²
- 36 lb bond 135 g/m²
- 30 lb text 44 g/m²
- 40 lb text 59 g/m²
- 45 lb text 67 g/m²
- 50 lb text 74 g/m²
- 55 lb text 81 g/m²
- 60 lb text 89 g/m²
- 70 lb text 104 g/m²
- 80 lb text 118 g/m²
- 100 lb text 148 g/m²
- 50 lb cover 135 g/m²
- 65 lb cover 176 g/m²
- 80 lb cover 216 g/m²
- 100 lb cover 27 g/m²
- 110 lb cover 297 g/m²
- 130 lb cover 352 g/m²
- 90 lb index 163 g/m²
- 110 lb index 199 g/m²
- 140 lb index 253 g/m²
Book paper in practice
Most print-on-demand book interiors use uncoated papers of roughly 50–60 lb text (74–90 g/m²). Colour interiors use heavier or coated stock. Paperback covers are typically 10–12 pt board (roughly 220–300 g/m²) with gloss or matte lamination.
Weight is not thickness: a bulky cream paper can be thicker than a smooth white sheet of the same weight, which is why spine widths differ by paper.