GSM (grams per square metre) vs LBS (pounds, basis weight)
Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.
Europe (universal), Asia (universal), most of the world. ISO standard.
US paper industry, Canadian paper industry. Always needs 'text' / 'cover' / 'bond' / 'index' qualifier.
| Aspect | GSM (grams per square metre) | LBS (pounds, basis weight) |
|---|---|---|
| Basis | Direct: g per m² | Parent sheet weight per 500 sheets |
| Universal across paper types | Yes | No |
| 80 lb 'text' | ≈ 118 gsm | 80 lb |
| 80 lb 'cover' | ≈ 216 gsm | 80 lb |
| Need qualifier? | No | Always |
Frequently asked
Why is US paper measurement so confusing?
Historical inheritance. Each paper type evolved its own 'parent sheet' size in the 19th-century US paper industry. 80 lb of book text paper, cover stock, and bond paper all weigh 80 pounds — but the parent sheet sizes differ, so the actual paper density differs. GSM eliminates this entirely.
What's a typical paper weight in gsm?
Office paper (printing): 80 gsm. Letterhead: 100-120 gsm. Business card: 300-400 gsm. Book pages: 70-100 gsm. Magazine cover: 200-300 gsm.
Frequently asked questions
Why is US paper measurement so confusing?
Historical inheritance. Each paper type evolved its own 'parent sheet' size in the 19th-century US paper industry. 80 lb of book text paper, cover stock, and bond paper all weigh 80 pounds — but the parent sheet sizes differ, so the actual paper density differs. GSM eliminates this entirely.
What's a typical paper weight in gsm?
Office paper (printing): 80 gsm. Letterhead: 100-120 gsm. Business card: 300-400 gsm. Book pages: 70-100 gsm. Magazine cover: 200-300 gsm.