Card Stock Weight and Size Calculator
Calculate card stock weight in GSM, points, and pounds.
Find the right thickness for invitations, business cards, and paper crafts.
Understanding card stock weight systems:
Card stock thickness is measured differently around the world, which causes endless confusion. The three main systems are GSM (grams per square meter), points (thousandths of an inch), and US pound weight (based on a ream of a specific base sheet size).
GSM (Grams per Square Meter): This is the international standard. It measures the weight of one square meter of paper in grams. Higher GSM = thicker, heavier paper. Regular copy paper is 75–90 GSM. Card stock starts at about 160 GSM.
US Pound Weight (Cover vs. Text): The US system is confusing because the base sheet size differs between “cover” stock and “text” stock. An 80 lb cover stock is much thicker than 80 lb text stock.
Conversion: Cover lb = GSM / 2.708. Text lb = GSM / 1.48.
Points (pt): One point = 1/1000 of an inch (0.001 in or 0.0254 mm). A 12 pt card is 0.012 inches thick. This is the most direct measure of thickness.
Approximate conversion: Points ≈ GSM / 11.5 (varies by paper density).
Reference table — common card stock uses:
| Use | GSM | Cover lb | Points |
|---|---|---|---|
| Flyers, inserts | 160–180 | 60 lb | 8–10 pt |
| Postcards | 200–250 | 80–90 lb | 10–14 pt |
| Invitations | 250–300 | 90–110 lb | 14–16 pt |
| Business cards | 300–400 | 110–148 lb | 14–18 pt |
| Premium packaging | 350–450 | 130–166 lb | 16–24 pt |
Worked example: You want to print wedding invitations on 270 GSM stock.
- Cover weight: 270 / 2.708 = ~100 lb cover
- Approximate points: 270 / 11.5 = ~23 pt
- This falls in the invitation range — sturdy enough to feel premium without being too stiff to fold.
Standard card stock sheet sizes:
- US Letter: 8.5 × 11 in (216 × 279 mm)
- A4: 8.27 × 11.69 in (210 × 297 mm)
- A5 (half-fold card): 5.83 × 8.27 in (148 × 210 mm)
- 12 × 12 in scrapbook: 305 × 305 mm
Tip: When choosing stock for a folding card, stay at or below 270 GSM. Heavier stock cracks when folded unless you score it first.