What Size is A5? Dimensions and Comparison Guide Sheet
Anyone who has ever grabbed a notebook and wondered why it feels bigger than a card but smaller than a letter is already close to the heart of A5. That’s because A5, as Canon’s paper-size explainer puts it, is the ISO size measuring 148 × 210 mm — half an A4 sheet folded once. The numbers matter because A5’s real job is practical: notebooks, cards, flyers, and print layouts that need to feel compact and readable.
A5 in centimeters: 14.8 × 21.0 cm ·
A5 in millimeters: 148 × 210 mm ·
A5 in inches: approx. 5.8 × 8.3 in ·
A5 surface area: 0.031 m² ·
ISO standard: ISO 216 ·
Aspect ratio: 1 : 1.414 (√2)
Quick snapshot
- A5 is half the area of A4 (Wikipedia’s A5 paper-size entry)
- A5 works as a flat card, flyer, or notebook page without folding (Wikipedia’s A5 paper-size entry)
- Some “A5 greeting cards” are trimmed or folded, so the finish size differs from a raw A5 sheet
- B5 comparisons depend on whether you mean ISO B5 or Japanese B5
- The ISO 216 standard keeps A5 fixed; the variable is your DPI setting when pixels
- For print, design A5 at 300 DPI; for screen previews 72 DPI
A5 is small enough to hold in one hand, and its dimensions were set with a ruler, not guesswork: 148 × 210 mm, about 5.83 × 8.27 in (Wikipedia’s A5 paper-size entry).
| Measurement | A5 value |
|---|---|
| ISO designation | A5 in the ISO 216 A-series |
| Width × height (mm) | 148 × 210 mm |
| Width × height (cm) | 14.8 × 21.0 cm |
| Width × height (in) | about 5.83 × 8.27 in |
| Area | 0.031 m² / 312.5 cm² / 48.43 sq in |
| Aspect ratio | 1 : √2 ≈ 1 : 1.414 |
| Relationship to A4 | exactly half by area; two A5 sheets tile one A4 |
| Relationship to A3 | one quarter area |
| Relationship to A6 / A7 | twice area of A6; four times area of A7 |
| Relationship to US Letter | smaller; Letter about 2.18 × A5 area |
What are the dimensions of A5 paper in centimeters?
A5 dimensions in millimeters, inches, and area
- Adobe’s A5 format reference lists A5 as 148 × 210 mm, or 14.8 × 21.0 cm, with an area of 0.031 m².
- That same sheet is about 5.83 × 8.27 in in imperial, just under the width of a standard 8.5 × 11 in US Letter page.
How A5 compares to other A-series sizes in dimension
- The A-series halving rule makes A5 exactly half A4 area and one quarter A3 area (Wikipedia’s paper-size overview).
- A5’s 210 mm long side is same as A4’s short side, two A5 sheets side by side recreate A4 without trimming.
A5’s numbers are not random: the same 148 × 210 mm rectangle is what you get when you fold an A4 sheet once. That’s why two A5 sheets always tile into one A4 without trimming.
The pattern: A5’s dimensions form bridge — the 148 mm side is A6’s long edge, the 210 side is A4’s short edge, while whole A-series locks together cleanly.
What are the ISO paper sizes?
A series sizes from A0 to A10
- The A-series starts with A0 at 841 × 1189 mm, a sheet with an area of about 1 m² (ISO 216:2007).
- Each following size is made by halving the longer side: A0 → A1 → A2 → A3 → A4 → A5.
Introduction to B-series and C series
- Beyond the A-series, ISO also defines B sizes for intermediate dimensions
- For A5 work, the C-series detail worth remembering a C5 envelope for an unfolded A5 sheet.
The term “A5” describes a physical sheet standard; it says nothing about paper weight, coating, or finish. Those choices belong to the print spec, not size name.
What this means: you don’t need to memorize every A-size; A5 is simply the size you get by halving A4, why it fits two-up on a standard office sheet.
Which size is bigger, A1, A2, A3, A4, A5?
Size ordering from largest
- From largest: A1 > A2 > A3 > A4 > A5
- The rule is simple: higher A number, smaller sheet, as defined by ISO 216.
How A4 compares to A5 and A3
- A4 is twice A5 by area.
- A3 is twice A4 area, making it four times A5.
- A2 is twice A3, A1 twice A2 — so A1 carries 16 A5 sheets by area.
The trade-off: A5 wins on portability but loses layout room. A4 gives a page about 42% more linear space in each direction, documents with dense type rarely feel comfortable at A5.
What size is A5 compared to A4?
Uses for A5 vs A4 in printing, notebooks and cards
- A4 measures 210 × 297 mm; A5 148 × 210 mm — because A4 short side equals A5 long side, two A5 pages sit exactly inside (Adobe’s A4 format reference).
- A5 is common for greeting cards, flyers, notebooks, and booklets; A4 is default for letters and office documents.
- A5 also smaller than US: US Letter is roughly 2.18 times A5 area.
Why this matters: if a client asks for an A5 flyer, you’re not just choosing a smaller page — you’re committing to less type, fewer images, sharper editing.
What size of A5 in pixels?
A5 pixel dimensions at 300 DPI for print
- At 300 DPI, A5 exports at 1748 × 2480 pixels (Instantprint’s print size guide).
A5 pixel dimensions at 300 DPI for digital display
- At 72 DPI, same A5 area becomes 420 × 595 pixels for screen preview.
Pixel conversions are DPI-dependent. At 300 DPI is 1748 × 2480 px; at 72 is 420 × 595 px — two very different exports of same paper size.
The takeaway: pixel dimensions only meaningful paired with DPI. Choose 300 for print and 72 for screen, and A5 rectangle stays same physical size.
The easiest way to feel A5 size is the halving rule: every step down the A-series halves area, so A1 holds 16 A5 sheets, A2 holds 8, A3 holds 4, A4 holds 2.
| Size | Area vs A5 | Typical use |
|---|---|---|
| A1 | 16 × A5 | posters, technical drawings |
| A2 | 8 × A5 | medium posters, diagrams |
| A3 | 4 × A5 | small posters, spreadsheets |
| A4 | 2 × A5 | letters, documents |
| A5 | 1 × A5 | notebooks, cards, flyers |
Designers often ask for pixels alongside millimeters, because same A5 sheet changes in pixels depending on DPI.
| Property | Value |
|---|---|
| ISO standard | ISO 216 A5 |
| Width × height (mm) | 148 × 210 mm |
| Width × height (cm) | 14.8 × 21.0 cm |
| Width × height (in) | about 5.83 × 8.27 in |
| A aspect ratio | 1 : √2 ≈ 1 : 1.414 |
| Area | 0.031 m² / 312.5 cm² / 48.43 sq in |
| Pixel at 300 DPI | 1748 × 2480 px |
| Pixel at 72 DPI | 420 × 595 px |
| Half by area of A4 | exactly half |
| Quarter area of A3 | one quarter |
| Letter vs | smaller; Letter about 2.18 × A5 |
What’s confirmed — and what still depends
Confirmed facts
- A5 base dimensions fixed by ISO 216: 148 × 210 mm.
- Two A5 sheets assemble into one A4 sheet with no waste.
What remains unclear
- Many “A5 greeting cards” sold as folded blanks or trimmed to fit envelopes, finished card can slightly smaller than raw A5 sheet.
- B5 comparisons require named standard: ISO B5 and Japanese B5 are different.
The pattern: A5 is precise standard on paper, but commercial products saying “A5” may adapt standard to product, not the other way.
What the standards say
A5 is half area of A4 when A4 divided across its shorter side.
Canon’s paper-size explainer
The A-series built on constant aspect ratio roughly 1:√2, so every halving keeps same shape.
ISO 216:2007
Why matters: every number above consistent because ISO system built on one ratio. If product veers from that ratio, technically no longer A5.
For anyone designing notebooks, printing flyers, or ordering greeting cards in bulk, A5 is not a compromise — it’s the smallest common size that still reads as a real page. One A4 sheet gives you two A5 sheets with zero waste, and one A5 sheet gives two A6 cards after folding. For designer, the decision is clear: choose A5 when you want portability and compact print product; choose A4 when page has to carry more layout, more type, more visual weight.
en.wikipedia.org, en.canon-cna.com, en.wikipedia.org, adobe.com, fr.wikipedia.org
Frequently asked questions
What is A5 paper used for?
A5 is common for notebooks, notecards, flyers, booklets, and place cards. Its compact shape suits short-form content that needs to be carried, handed out, or mailed without folding.
How many A5 sheets fit in one A4 sheet?
Two. An A4 sheet divided across its shorter side gives two A5 sheets with no waste.
Is A5 the same as half of US Letter?
No. US Letter is 8.5 x 11 in, A5 about 5.83 x 8.27 in. US Letter has roughly 2.18 times area of A5.
What’s A5 pixel size at 300 DPI?
At 300 DPI, full A5 print area is 1748 × 2480 pixels. At 72 DPI, physical sheet becomes 420 × 595 pixels on screen.
Is A5 standard greeting card size?
A5 common base size for card blanks, but finished cards often fold or trim sheet. An A5 blank folded in half creates A6 front panel, so check flat size before ordering.
Which is bigger: A5 or B5?
B5 is larger in ISO B series. If someone quotes B5 without naming standard, check whether ISO B5 or Japanese B5, because the two are not same.
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