Convert between different paper weight systems (GSM, pounds, grams, etc.). Compare paper thickness and weight for printing and crafting.
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GSM (g/m²)
0 g/m²
Standard international weight
Bond / Ledger
0 lbs
Common office paper
Text / Book
0 lbs
Book pages & flyers
Cover
0 lbs
Cardstock & covers
Index
0 lbs
Index cards & tags
Tag
0 lbs
Tags & heavy stock
📄 Equivalent Common Paper Type
—
Estimated Thickness0 microns
Thin (30 g/m²)Standard (80 g/m²)Thick (300 g/m²)
📝 Conversion Steps
Real-World Paper Weight Examples
📄 Standard Office Copy Paper
A typical office printer paper has a weight of 75–80 GSM.
Equivalent Bond Weight:≈ 20 lb Bond
Equivalent Text Weight: ≈ 50–54 lb Text
Equivalent Cover Weight: ≈ 28–30 lb Cover
Thickness: Approximately 100 microns (0.1 mm)
This is the most common paper used for everyday printing, copying, and general office use.
📁 Business Card / Heavy Cardstock
A sturdy business card or postcard uses paper around 250–350 GSM.
Equivalent Cover Weight:≈ 92–129 lb Cover
Thickness: Approximately 330–460 microns (0.33–0.46 mm)
Cardstock weight varies significantly — 12pt (≈ 270 GSM) is common for postcards while 14pt (≈ 350 GSM) is typical for premium business cards.
📖 Paperback Book Pages
Most paperback novels use 60–90 GSM text-weight paper.
Equivalent Text Weight:≈ 40–60 lb Text
Equivalent Bond Weight: ≈ 16–24 lb Bond
Lighter weight paper (60 GSM) is often used for mass-market paperbacks to keep book thickness manageable, while 80–90 GSM is used for trade paperbacks for a more premium feel.
🏷️ Index Cards
Standard index cards are made from 90–110 lb Index paper.
Equivalent GSM:≈ 163–199 GSM
Equivalent Cover Weight: ≈ 60–73 lb Cover
Index paper is stiffer than bond or text paper of the same weight due to its denser fiber structure and higher caliper.
Understanding Paper Weight Systems
Paper weight can be confusing because different regions and paper types use different measurement systems. The two main systems are GSM (grams per square meter) — an international standard — and the pound (lb) system — a US-based system that varies by paper type (bond, text, cover, index, tag).
Key Conversion Formulas
GSM = Bond lbs × 3.76
Bond/Ledger paper (basis size: 17 × 22 in)
GSM = Text lbs × 1.48
Text/Book paper (basis size: 25 × 38 in)
GSM = Cover lbs × 2.71
Cover paper (basis size: 20 × 26 in)
GSM = Index lbs × 1.81
Index paper (basis size: 25.5 × 30.5 in)
GSM = Tag lbs × 1.63
Tag paper (basis size: 24 × 36 in)
Paper Weight Systems Reference
System
Abbreviation
Basis Size
Common Uses
GSM
g/m²
1 m² (standard)
International standard, all paper types
Bond / Ledger
lb
17 × 22 in
Office paper, letterhead, stationery
Text / Book
lb
25 × 38 in
Book pages, brochures, flyers
Cover
lb
20 × 26 in
Cardstock, postcards, business cards
Index
lb
25.5 × 30.5 in
Index cards, tags, dividers
Tag
lb
24 × 36 in
Tags, heavy-duty paper stock
How to Convert Paper Weight Step by Step
1
Identify your starting system: Determine whether your paper weight is in GSM, Bond lbs, Text lbs, Cover lbs, Index lbs, or Tag lbs.
2
Convert to GSM first: Apply the appropriate conversion factor to convert your value to GSM (grams per square meter) — the universal base unit.
3
Convert from GSM to target system: Once you have GSM, divide by the appropriate factor to get the equivalent weight in the target pound system.
4
Estimate thickness: Paper thickness in microns ≈ GSM × 1.3 (for uncoated paper) or GSM × 0.67 (for coated paper). Thickness varies by paper composition.
5
Compare to common paper types: Use the equivalent paper type matching to understand what your converted weight means in practical terms — e.g., 75 GSM ≈ 20 lb Bond (standard copy paper).
Quick Tips
⚖️ GSM is Universal
GSM (grams per square meter) is the international standard. Always convert to GSM first when comparing different paper weight systems.
📐 Different Basis Sizes
The pound (lb) weight is the weight of 500 sheets of paper in its uncut basis size. Different paper types have different basis sizes, which is why 80 lb Cover is much thicker than 80 lb Text.
📏 Caliper vs Weight
Paper weight (GSM/lb) measures mass, not thickness. Two papers with the same GSM can have different thicknesses depending on density, coating, and fiber composition.
🖨️ Printer Compatibility
Most home printers can handle up to 120 GSM (≈ 32 lb Bond). Heavier papers (cardstock) may require a specialty printer or manual feed.
📄
Multi-System Conversion
Convert between GSM, Bond, Text, Cover, Index, and Tag paper weight systems instantly with a single click.
📏
Thickness Estimate
Get an estimated paper thickness in microns with a visual thickness bar comparing your paper to standard weights.
🏷️
Paper Type Matching
Discover equivalent common paper types — instantly see if your weight matches standard office paper, cardstock, index cards, and more.
📚
Formula & Reference Guide
Built-in conversion formulas and a complete reference table for all paper weight systems and their basis sizes.
Paper weight refers to the mass or density of paper, typically expressed in grams per square meter (GSM or g/m²) in most countries, or in pounds (lb) in the United States and some other regions. Understanding paper weight is essential for choosing the right paper for printing, crafting, packaging, and other applications.
The key distinction to understand is that paper weight is not the same as paper thickness. While heavier paper is generally thicker, two papers with the same GSM can have different thicknesses depending on their composition, density, and surface treatment (coated vs. uncoated). This is why our calculator provides both a weight conversion and a thickness estimate.
Why Paper Weight Matters
Choosing the right paper weight affects everything from print quality and durability to postage costs and the tactile feel of your finished project. Lightweight paper (under 80 GSM) is economical for everyday printing and copying. Mid-weight paper (80–120 GSM) offers a more premium feel for letterhead, brochures, and presentations. Heavyweight paper (over 120 GSM) provides stiffness and durability for business cards, postcards, invitations, and packaging.
The Pound (lb) System Explained
The US pound system can be confusing because the same number can mean very different weights depending on the paper type. For example, 20 lb Bond paper is a lightweight office paper (≈ 75 GSM), while 20 lb Cover paper would be relatively heavy cardstock (≈ 54 GSM — which is actually lighter than bond because Cover uses a smaller basis size). This is because each paper type uses a different basis size — the standard sheet size for that type of paper.
Bond/Ledger: Basis size 17 × 22 inches — used for letterhead, stationery, office paper
Text/Book: Basis size 25 × 38 inches — used for book pages, brochures, flyers
Cover: Basis size 20 × 26 inches — used for cardstock, book covers
Index: Basis size 25.5 × 30.5 inches — used for index cards, dividers
Tag: Basis size 24 × 36 inches — used for tags, heavy stock
How to Choose the Right Paper Weight
Selecting the best paper weight depends on your specific project needs. Here's a practical guide to help you decide:
📝 Everyday Printing (60–90 GSM)
Ideal for internal documents, drafts, and high-volume printing. 75–80 GSM (≈ 20 lb Bond) is the standard for office copy paper.
📬 Professional Documents (90–120 GSM)
Perfect for letterhead, resumes, presentations, and client-facing materials. These papers feel more substantial and print with less show-through.
🏷️ Light Cardstock (120–200 GSM)
Suitable for flyers, menus, greeting cards, and high-quality brochures. Still flexible enough for most home printers.
💳 Heavy Cardstock (200–350 GSM)
Best for business cards, postcards, invitations, and packaging. Requires a printer with a straight paper path or manual feed for best results.
Frequently Asked Questions
What does GSM mean in paper weight?
GSM stands for grams per square meter. It is the international standard for measuring paper weight and density. Unlike the US pound system, GSM is a direct measurement — it tells you exactly how much one square meter of that paper weighs in grams. This makes GSM the most reliable way to compare paper weights across different types and brands.
What's the difference between 20 lb Bond and 20 lb Cover?
Despite having the same number, 20 lb Bond and 20 lb Cover are very different papers. This is because each uses a different basis size. 20 lb Bond has a basis size of 17 × 22 inches and equals about 75 GSM — standard office paper. 20 lb Cover has a basis size of 20 × 26 inches and equals only about 54 GSM. So 20 lb Cover is actually lighter than 20 lb Bond! The pound system only makes sense when comparing paper within the same type.
How do I convert between paper weight systems?
The easiest way is to first convert everything to GSM, then convert from GSM to the target system. The conversion factors are: GSM = Bond lbs × 3.76, GSM = Text lbs × 1.48, GSM = Cover lbs × 2.71, GSM = Index lbs × 1.81, and GSM = Tag lbs × 1.63. Our Paper Weight Calculator handles all these conversions automatically for you.
Is paper thickness the same as paper weight?
No, paper thickness (caliper) and paper weight (GSM/lb) are different measurements. Weight measures mass per area, while thickness measures physical height. Two papers with the same GSM can have different thicknesses depending on fiber composition, density, and whether the paper is coated or uncoated. Coated papers are typically denser and thinner than uncoated papers of the same GSM. Our calculator provides a thickness estimate for reference.
What paper weight should I use for business cards?
Business cards typically use 300–350 GSM (≈ 110–130 lb Cover) paper. This weight provides the stiffness and durability expected of a professional business card. For premium cards, some use 400 GSM or higher (14pt+). Lighter weights (200–250 GSM) can feel flimsy and may not leave the right impression. Always check your printer's specifications before printing heavy cardstock.
Can my home printer handle heavy paper?
Most standard home printers can handle paper up to about 120 GSM (≈ 32 lb Bond) through the regular paper tray. For heavier papers (120–200 GSM), use the manual feed or rear paper slot if available. Papers over 200 GSM (cardstock) may require a printer specifically designed for heavy media, or you may need to use a professional printing service. Always check your printer's specifications for maximum paper weight.