Convert US Paper Weight to European GSM
Working with a European printer? This converter helps US publishers, designers, and print buyers convert familiar pound weights to the metric GSM (grams per square meter) system used internationally.
Need to convert the other way? Visit our European to US Paper Weight Converter
US to GSM Calculator
European Metric Weight
How This Works
US paper weights are based on the weight of 500 sheets (a ream) cut to a specific "basis size" that varies by paper type. GSM is simpler – it's always the weight of one square meter of paper, regardless of sheet size.
Formula: GSM = (Basis Weight × 1406.5) ÷ (Sheet Width × Sheet Length)
Common US to GSM Conversions for Book Production
Text/Book Papers (25" × 38" basis)
| US Weight (lbs) | GSM | Typical Book Use |
|---|---|---|
| 30 lb text | 44 GSM | Bible paper, dictionaries |
| 40 lb text | 59 GSM | Mass market paperbacks |
| 45 lb text | 67 GSM | Light paperbacks |
| 50 lb text | 74 GSM | Standard paperbacks |
| 60 lb text | 89 GSM | Trade paperbacks |
| 70 lb text | 104 GSM | Premium hardcovers |
| 80 lb text | 118 GSM | Art books, photo books |
| 90 lb text | 133 GSM | Premium art books |
| 100 lb text | 148 GSM | Heavy text, light card |
| 120 lb text | 178 GSM | Extra heavy text |
Cover Papers (20" × 26" basis)
| US Weight (lbs) | GSM | Typical Book Use |
|---|---|---|
| 65 lb cover | 176 GSM | Standard paperback covers |
| 80 lb cover | 216 GSM | Premium paperback covers |
| 100 lb cover | 270 GSM | Heavy covers, dust jackets |
| 110 lb cover | 298 GSM | Premium card stock |
| 130 lb cover | 352 GSM | Board book covers |
Bond/Writing Papers (17" × 22" basis)
| US Weight (lbs) | GSM | Typical Use |
|---|---|---|
| 16 lb bond | 60 GSM | Thin paper, endpapers |
| 20 lb bond | 75 GSM | Standard copy paper |
| 24 lb bond | 90 GSM | Premium letterhead |
| 28 lb bond | 105 GSM | Heavy stationery |
| 32 lb bond | 120 GSM | Premium stationery |
Remember
Always specify both the weight and the paper type when communicating with printers. "80 lb" could mean 80 lb text (118 GSM) or 80 lb cover (216 GSM) – a significant difference!
Tips for Working with European Printers
- • European printers exclusively use GSM – no need to specify paper type
- • Common European book weights: 70-90 GSM for text, 200-300 GSM for covers
- • ISO paper sizes (A4, A5) differ from US letter and book sizes
- • European binding specifications may differ – confirm spine calculations
- • Ask about paper opacity – European papers may have different opacity at the same weight
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