Index Card Sizes and Dimensions
In short: the standard index card is 3 × 5 inches (7.6 × 12.7 cm). The other two common sizes are 4 × 6 in (10.2 × 15.2 cm) and 5 × 8 in (12.7 × 20.3 cm). Outside the US, A7 (7.4 × 10.5 cm) and A6 (10.5 × 14.8 cm) are the nearest equivalents. Need cards now? Print them at true size.
Index card size chart
All dimensions are width × height with the card held landscape. Checked November 2026 against major US and EU stationery brands.
| Feature | 3 × 5 in | 4 × 6 in | 5 × 8 in | A7 | A6 |
|---|---|---|---|---|---|
| Inches | 3 × 5 | 4 × 6 | 5 × 8 | 2.9 × 4.1 | 4.1 × 5.8 |
| Centimetres | 7.6 × 12.7 | 10.2 × 15.2 | 12.7 × 20.3 | 7.4 × 10.5 | 10.5 × 14.8 |
| Millimetres | 76.2 × 127 | 101.6 × 152.4 | 127 × 203.2 | 74 × 105 | 105 × 148 |
| Ruled lines (approx.) | 8–9 | 12–13 | 15–16 | 7–8 | 11–12 |
| Per sheet | 3 per Letter | 2 per Letter | 1–2 per Letter | 4 per A4 | 2 per A4 |
| Common in | US, Canada | US, Canada | US, Canada | UK, EU | UK, EU |
| Best for | Flashcards, recipes | Speech notes, summaries | Outlines, lesson plans | Vocabulary cards | Revision cards |
The three US sizes, drawn to scale
- 3 × 5: fits a shirt pocket and a standard recipe box. The flashcard default.
- 4 × 6: the same as a standard photo print. Room for a formula, a small diagram or speaker notes in large type.
- 5 × 8: half of a US Letter sheet folded. Used for outlines, storyboards and teacher notes.
Ruled, blank, grid or colored?
| Feature | Ruled | Blank | Grid | Colored |
|---|---|---|---|---|
| What it looks like | Red headline + blue lines | Plain white | 1/4 in squares | Ruled or blank in pastel colors |
| Best for | Flashcards, notes | Drawing, labels, games | Math, charts, diagrams | Sorting topics or decks |
| Tip | Term above the red line, answer below | Use the back for answers | Graph small functions | One color per subject |
How to print on index cards
- Step 1
Set the page size
In the print dialog, pick a custom size that matches the card (5 × 3 in for a landscape 3 × 5). Our template sets it for you.
- Step 2
Load the rear tray
Feed card stock through the manual or rear tray; it bends less than the main cassette. Mark the top of one card to learn the feed direction.
- Step 3
Print at 100%
Choose Actual size, not Fit to page, and turn off headers and footers. Print one test card before the stack.
No card stock? The index card template prints three 3 × 5 cards per Letter sheet with cut lines. For study cards, let AI write them from your notes with the AI flashcard maker, then print them as fold-over cards.
Ways to use index cards for studying
- Flashcards: one question per card, answer on the back. Sort into “know” and “not yet” piles and review the second pile more often (the Leitner system).
- Vocabulary: word on the front; meaning, a sentence and the part of speech on the back.
- Formula cards: 4 × 6 leaves room for the formula, the variables and one worked example.
- Speech notes: one point per card in large letters, numbered in the corner in case you drop them.
- Essay planning: one quote or idea per 3 × 5 card, then arrange them on a table to find your outline.
Index card FAQ
What is the standard index card size?
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In the US the standard index card is 3 × 5 inches (76.2 × 127 mm, or 7.6 × 12.7 cm). The other common sizes are 4 × 6 in (101.6 × 152.4 mm) and 5 × 8 in (127 × 203.2 mm). Outside North America the closest standard sizes are A7 (74 × 105 mm) and A6 (105 × 148 mm).
How big is a 3x5 index card in cm?
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7.62 × 12.7 cm (76.2 × 127 mm). It is slightly larger than an A7 card (7.4 × 10.5 cm) and a little smaller than a postcard.
Is a 4x6 index card the same size as A6?
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Close, but not the same. A 4 × 6 card is 101.6 × 152.4 mm; A6 is 105 × 148 mm, so A6 is about 3 mm wider and 4 mm shorter. Both fit standard 4 × 6 photo boxes and card holders, and both work for speech notes.
How many index cards can I cut from one sheet of paper?
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From US Letter (8.5 × 11 in): three 3 × 5 cards, two 4 × 6 cards, or one 5 × 8 card with room to spare (two if you accept a narrow trim). From A4: four A7 cards or two A6 cards. Our index card template draws them at true size with cut lines.
How many lines are on a ruled index card?
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Ruled cards have a red headline and blue lines about 1/4 inch (6.35 mm) apart: roughly 8–9 lines on a 3 × 5, 12–13 on a 4 × 6 and 15–16 on a 5 × 8. Some brands use a wider 9/32 in rule.
What size index cards are best for flashcards?
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3 × 5 is the classic flashcard size: big enough for a term and a short definition, small enough to carry a stack. Use 4 × 6 if your answers are long (formulas, diagrams) and 5 × 8 for summary cards or outlines.
Can I print on index cards with a normal printer?
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Yes. Most inkjet and laser printers accept 3 × 5 and 4 × 6 card stock through the rear or manual feed tray. Set a custom paper size that matches the card, scale to 100%, and print one test card first to see which side and direction your printer uses.