Book printing paper tool
Paper Weight Converter
Convert GSM, lb, and pt into practical paper stock options. Use this tool to compare paper weights, understand text paper vs cover stock, and choose a better fit before printing.
Useful for book pages, softcover covers, dust jackets, brochures, postcards, and business cards.
Paper Weight Converter
Choose a weight or thickness conversion, enter a number, and select the paper family when lb is involved.
Weight conversion
Thickness estimate
Common Book Paper Weight Chart
These are practical equivalents for common book printing specs. Use the chart as a quick reference before choosing paper for interiors, covers, dust jackets, cards, or other printed pieces.
| US Paper Weight | Closest Available GSM | Common Use | How to Choose |
|---|---|---|---|
| 50 lb text | 70 gsm | Novels, manuals, text heavy pages | Light and economical. Good when page count or shipping weight matters. |
| 55 lb text | 80 gsm | Novels, nonfiction, general reading books | A common everyday text paper with a little more body than 50 lb. |
| 60 lb text | 90 gsm | Manuals, workbooks, general interiors | Good when you want pages to feel less thin without adding too much weight. |
| 65 lb text | 100 gsm | Journals, workbooks, standard interiors | A balanced paper weight for many general printed pages. |
| 70 lb text | 105 gsm | Catalogs, guides, image heavy pages | Adds more substance while still keeping the pages flexible. |
| 80 lb text | 120 gsm | Premium booklets, catalogs, color pages | Good when images need a nicer feel but the pages still need to turn easily. |
| 85 lb text | 128 gsm | Children's books, art books, premium interiors | A strong choice for color heavy pages and illustrated books. |
| 100 lb text | 150 gsm | Premium brochures, short booklets, heavy interiors | Thick for inside pages. Better for shorter projects. |
| 105 lb text | 157 gsm | Coffee table book, premium interiors, dust jackets, end sheets | Thick and substantial. Good when you want a heavier page feel. |
| 65 lb cover | 175 gsm | Light covers, flyers, menus | Thicker than text paper, but still fairly flexible. |
| 80 lb cover | 215 gsm | Light softcover covers, postcards, menus | Good when you need cover stock but do not need a very stiff feel. |
| 100 lb cover | 270 gsm | Softcover covers, postcards, business cards | Very common local printer cover stock. Good general cardstock feel. |
| 110 lb cover | 300 gsm | Premium covers, cards, postcards | Stiffer and more substantial than 100 lb cover. |
| 120 lb cover | 325 gsm | Premium business cards, postcards, heavy covers | Good when the piece needs to feel thicker and more premium. |
| 130 lb cover | 350 gsm | Thick cards, premium covers, heavy cover stock | Heavy cardstock feel. Good for durability and premium presentation. |
| 10 pt cover stock | about 250 gsm | Light postcards, rack cards, light covers | A print shop thickness term. Good for lighter cardstock projects. |
| 12 pt cover stock | about 250 to 300 gsm | softcover covers, saddle stitch covers, postcards | A common cover thickness for many printed pieces. |
| 14 pt cover stock | about 300 to 350 gsm | Business cards, postcards, premium covers | Good when the piece needs a thicker cardstock feel. |
| 16 pt cover stock | about 350 to 400 gsm | Premium business cards, thick postcards | Feels more rigid and premium than standard cover stock. |
| 18 pt cover stock | about 400 to 450 gsm | Extra thick cards and premium print pieces | Use when stiffness and premium feel are more important than flexibility. |
This chart shows the closest real world paper stock equivalents. Calculator results may differ because mills sell standard stock labels, not exact math conversions.
Understanding GSM, LB, and PT
Paper conversion is useful, but it needs the right assumptions.
GSM (grams per square meter) is the cleanest unit. It measures the weight of one square meter of paper. That makes it easier to compare paper across printers and countries.
LB (pounds) depends on the paper type. The same lb number can mean different things. For example, 100 lb text is a heavy interior paper, while 100 lb cover is a cardstock used for covers, cards, and postcards.
PT (points) measures thickness, not weight. A 14 pt sheet is about thickness, not paper weight. GSM is about weight. Coating, density, and paper construction can change the relationship, so pt to GSM should be treated as a stock estimate.
Paper Weight Converter FAQ
Quick answers for common lb, GSM, and pt conversion questions.
Why can't I always choose the exact GSM converted from lb?
The exact lb to GSM conversion is a math result, but paper mills usually sell standard paper stocks.
For example, 105 lb text converts to about 155 gsm by math, but the closest commonly available stock may be sold as 157 gsm. In real printing, you usually choose the closest available paper instead of matching the calculator number exactly.
That is why the calculator is helpful for comparison, but the chart is often more practical when choosing paper.
Where does the lb number in paper weight come from?
In U.S. paper specs, the lb number comes from the weight of 500 sheets at a standard parent sheet size before the paper is cut down.
The confusing part is that each paper type uses a different standard size. Text paper is commonly measured from a 25 x 38 inch sheet. Cover stock is commonly measured from a 20 x 26 inch sheet.
So 80 lb text means 500 sheets of 25 x 38 inch text paper weigh 80 lb. 80 lb cover means 500 sheets of 20 x 26 inch cover stock weigh 80 lb. Your final printed sheet does not need to be that size. This is just the reference size used to name the paper weight.
What is basis size in paper weight?
Basis size is the standard reference sheet size used to calculate U.S. lb paper weight. It is not the final size of your printed piece.
For example, text paper commonly uses a 25 x 38 inch basis size. Cover stock commonly uses 20 x 26 inches. Bond paper, often used for copy paper, commonly uses 17 x 22 inches.
The lb number means 500 sheets of that basis size weigh that many pounds. Because each paper family uses a different basis size, 80 lb text, 80 lb cover, and 80 lb bond do not mean the same paper weight.
What GSM paper is used for board books?
For our standard board book printing, we use two 350 gsm sheets. Each sheet is printed on one side, then the two sheets are glued together and compressed into an approximately 1 mm thick board page.
Together, the two sheets are roughly 700 gsm before compression, which is far beyond standard book interior paper. This is a common way to make a thicker, stiffer printed piece when a single sheet is not enough.
Should I always choose heavier paper if I want better quality?
Not always. Heavier paper can feel nicer, but it also makes the finished piece thicker, heavier, and sometimes more expensive.
For long page counts, lighter paper may be more practical. For projects where page feel, color, or durability matters more, heavier paper may be a better fit.
The best paper weight is not always the highest number. It depends on the project, binding, and how the finished piece should feel.
Want to see and feel the papers we offer?
Order our sample pack to compare paper weights, finishes, and book samples before choosing your specs.