Paper Weight Converter
Convert paper weight between GSM, US bond weight, and US cover weight.
With a reference chart of paper types from 75 GSM copy paper to 350 GSM cardstock.
Type in any field — the others update instantly.
Paper weight is measured differently in each region.
GSM (grams per square meter): The international standard. Used worldwide. Higher GSM = thicker, heavier paper.
US Bond Weight (lb): Based on 500 sheets of 17" × 22" paper.
- Conversion: GSM = Bond weight × 3.7597
US Cover Weight (lb): Based on 500 sheets of 20" × 26" paper.
- Conversion: GSM = Cover weight × 2.7048
Common paper weights:
| Paper Type | GSM | US Bond (lb) | US Cover (lb) |
|---|---|---|---|
| Thin copy paper | 75 gsm | 20 lb | — |
| Standard copy | 80 gsm | 21 lb | — |
| Letterhead | 90 gsm | 24 lb | — |
| Premium paper | 100 gsm | 27 lb | — |
| Light card | 120 gsm | 32 lb | 44 lb |
| Index card | 160 gsm | 43 lb | 59 lb |
| Light cardstock | 200 gsm | 53 lb | 74 lb |
| Business card | 300 gsm | 80 lb | 111 lb |
| Heavy cardstock | 350 gsm | 93 lb | 129 lb |
US paper weight is confusing because it depends on the “basis size” which differs between bond and cover stocks.
Why the pound numbers seem contradictory: A “20 lb” bond sheet and a “50 lb” text sheet are the same everyday copy paper, about 75 gsm. Each US category weighs 500 sheets at its own basis size (bond at 17" × 22", text at 25" × 38", cover at 20" × 26"), so the pound figures only compare within a single category. That is why an 80 lb text flyer bends easily while an 80 lb cover card feels stiff. GSM cuts through all of it: one number, one square meter, any paper. If you run into US text weight, multiply the pound value by 1.48 to get GSM.
Picking a weight your printer can handle: Most home inkjets and lasers feed anything up to about 200 gsm without complaint. Push past that and you risk jams or faded toner, because a stiff sheet will not bend around the rollers properly. Check the spec before buying 300 gsm cardstock for a home project; many printers cap out around 220 gsm, sometimes only through the rear tray. Print shops handle the heavy stocks routinely, which is one good reason business cards and invitations are usually outsourced.
How we build and check this converter
This converter 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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