Paper Weight Converter
Convert paper weight between GSM (grams per square meter) and US basis weight in pounds for any paper type.
Paper Weight Conversion
Paper weight is measured differently in different countries. Most of the world uses GSM (grams per square meter), while the US uses basis weight in pounds.
GSM (Metric): Measures the weight in grams of one square meter of paper. Simple and universal. Higher number = thicker, heavier paper.
Basis Weight (US): Measures the weight in pounds of 500 sheets (a ream) at the paper type’s standard sheet size. The standard sheet size varies by paper type, which makes this system confusing.
Standard base sizes by paper type:
| Paper Type | Base Sheet Size | Common Weights |
|---|---|---|
| Bond/Writing | 17 x 22 inches | 20, 24, 28 lb |
| Text/Book | 25 x 38 inches | 50, 60, 70, 80 lb |
| Cover/Card | 20 x 26 inches | 65, 80, 100 lb |
| Bristol | 22.5 x 28.5 inches | 67, 80, 100 lb |
Conversion formula:
GSM = Basis Weight (lbs) x Conversion Factor
| Paper Type | Multiply lbs by |
|---|---|
| Bond | 3.76 |
| Text | 1.48 |
| Cover | 2.70 |
| Bristol | 2.19 |
Common equivalents:
- 20 lb bond = 75 GSM (standard copy paper)
- 24 lb bond = 90 GSM (nicer letterhead)
- 80 lb text = 118 GSM (quality brochure)
- 80 lb cover = 216 GSM (business cards)
- 100 lb cover = 270 GSM (thick cards)