Print Trail

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

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)GSMTypical Book Use
30 lb text44 GSMBible paper, dictionaries
40 lb text59 GSMMass market paperbacks
45 lb text67 GSMLight paperbacks
50 lb text74 GSMStandard paperbacks
60 lb text89 GSMTrade paperbacks
70 lb text104 GSMPremium hardcovers
80 lb text118 GSMArt books, photo books
90 lb text133 GSMPremium art books
100 lb text148 GSMHeavy text, light card
120 lb text178 GSMExtra heavy text

Cover Papers (20" × 26" basis)

US Weight (lbs)GSMTypical Book Use
65 lb cover176 GSMStandard paperback covers
80 lb cover216 GSMPremium paperback covers
100 lb cover270 GSMHeavy covers, dust jackets
110 lb cover298 GSMPremium card stock
130 lb cover352 GSMBoard book covers

Bond/Writing Papers (17" × 22" basis)

US Weight (lbs)GSMTypical Use
16 lb bond60 GSMThin paper, endpapers
20 lb bond75 GSMStandard copy paper
24 lb bond90 GSMPremium letterhead
28 lb bond105 GSMHeavy stationery
32 lb bond120 GSMPremium 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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