Paper Weight Converter — GSM to lb
Convert paper weight between GSM, lb text, lb cover, and lb bond.
Find the right paper weight for printing, crafting, cardstock, and packaging projects.
Paper Weight Explained
Paper weight is measured differently in the US vs the rest of the world. The US system is based on the weight of 500 sheets cut to a standard parent sheet size. The metric system uses GSM: grams per square meter — universal and logical.
Conversion factors:
| From | To GSM | Formula |
|---|---|---|
| lb text (offset) | x 1.48 | 25x38 in parent sheet |
| lb cover | x 2.72 | 20x26 in parent sheet |
| lb bond (writing) | x 3.76 | 17x22 in parent sheet |
Examples:
- 20 lb bond (copy paper) = 75 gsm
- 24 lb bond (premium copy) = 90 gsm
- 65 lb cover (thin cardstock) = 176 gsm
- 80 lb cover (standard cardstock) = 216 gsm
- 100 lb cover (heavy cardstock) = 271 gsm
Common paper types by GSM:
| GSM | Type | US Equivalent |
|---|---|---|
| 30-45 | Tissue, tracing paper | , |
| 45-55 | Newsprint | , |
| 60-70 | Lightweight book | 40-45 lb text |
| 75-90 | Copy/printer paper | 20-24 lb bond |
| 90-120 | Premium printer | 60-80 lb text |
| 130-160 | Flyer, brochure | 90-100 lb text |
| 160-200 | Light cardstock | 60-75 lb cover |
| 200-250 | Standard cardstock | 80-90 lb cover |
| 270-350 | Heavy cardstock | 100-130 lb cover |
| 350-400 | Board, poster | , |
Why two US systems (text vs cover)? Text weight uses a larger parent sheet than cover weight. The same paper measured on different parent sheets gives different lb numbers. This is why 80 lb text does NOT equal 80 lb cover — cover is much heavier.
Buying tip: Always check GSM when ordering paper from international suppliers. US lb weights without specifying text vs cover vs bond are ambiguous.
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This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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