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Notebook sizes explained
A5 is half of A4 and B5 sits between them. Once you know how the two series relate, every size on the shelf makes sense.
How the A series works
The A series starts at A0, which is one square meter of paper. Each subsequent size is that sheet folded in half along its longer side: A1 is half of A0, A2 is half of A1, and so on down.
Because the halving is always along the long side, every size in the series has the same proportions. That is the elegant part of the system and the reason a page of A5 scales perfectly onto A4 without cropping.
How the B series works
The B series is the same idea, sized so that each B sits between two A sizes. B5 is larger than A5 and smaller than A4; B6 is larger than A6 and smaller than A5.
That is why B sizes feel like the answer to a question you did not know you had. B5 in particular is the size most people should be writing longhand on, and almost nobody in Western stationery has met it — it is the standard Japanese student notebook.
Which size is for what
| Size | Roughly | Best for | Against it |
|---|---|---|---|
| A6 | Lists, a carried notebook, quick capture | Too small for a real entry | |
| B6 | A little larger than pocket | A daily log, a travel journal | Cramped for long-form prose |
| A5 | Half a sheet of letter paper | The default journal size — big enough to write, small enough to carry | A desk book it is not |
| B5 | Between A5 and A4 | Longhand at a desk, study notes | Fits no A-series folder |
| A4 | A sheet of letter paper | Drafting, diagrams, printed forms | Too big to carry comfortably |
Why B5 suits handwriting specifically
A wider page means fewer line breaks, and fewer line breaks mean fewer places where the nib stops, changes direction and deposits a small blob of ink. Long uninterrupted strokes are where a fountain pen is at its best.
There is a second reason, and it is about paper rather than geometry: most B5 notebooks in circulation are Japanese, and Japanese paper at a given weight is denser and more tightly sized than European office stock. The size and the paper tradition travel together — our B5 roundup covers the options.
Quick picks
Ranked for the beginner buying their first setup. Every pick names who it is wrong for.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | No image Maruman Mnemosyne hardcover A5, dot grid 240 pages of published 90 g/m2 Japanese paper in a thread-bound hardcover, with the dot spacing stated too. | A hardcover dot grid with the weight published | Check price on Amazon #ad No live price right now. How this is funded |
| 2 | No image Kokuyo Campus B5, ruled The Japanese school notebook, in B5, at a price that makes writing a hundred pages feel free. | Volume writing on a budget | Check price on Amazon #ad No live price right now. How this is funded |
| 3 | No image Stalogy 365 Days Notebook B6 A thin-paper daily notebook with a full year of dated grid pages in a book you can still carry. | One book for a whole year | Check price on Amazon #ad No live price right now. How this is funded |
1. A hardcover dot grid with the weight published
Maruman Mnemosyne hardcover A5, dot grid
240 pages of published 90 g/m2 Japanese paper in a thread-bound hardcover, with the dot spacing stated too.
#ad No live price right now. How this is funded
This is the notebook that answers the most common complaint about the structured-journal category: it publishes 90 g/m2, which is comfortably above what a wet nib needs, and it states the dot spacing as well.
Japanese 90 gsm is dense and tightly sized, so it sits at the top of what this site can recommend on published figures alone rather than on reputation.
What it does not have is numbered pages or a printed index. If you want a bullet-journal system out of the box, that is a different purchase.
| Paper weight | 90 g/m2, acid-freeSource: Maruman Mnemosyne hardcover A5 dot grid (retail listing, read 2026-09-01) |
|---|---|
| Ruling | 5 mm dot gridSource: Maruman Mnemosyne hardcover A5 dot grid (retail listing, read 2026-09-01) |
| Extent | 120 sheets (240 pages), A5Source: Maruman Mnemosyne hardcover A5 dot grid (retail listing, read 2026-09-01) |
| Binding | Thread-bound hardcover, with a bookmark and elastic closureSource: Maruman Mnemosyne hardcover A5 dot grid (retail listing, read 2026-09-01) |
What it does well
- Published 90 g/m2 and a published 5 mm dot spacing
- 240 pages, thread-bound, with a bookmark and elastic
- Hardcover that survives a bag
What it does not
- No numbered pages or index
- Heavier and thicker than the spiral version
- Less widely stocked than the market leaders
Skip this if you want numbered pages and a printed index — buy a Goalbook or a Dingbats instead and accept their paper.
2. Volume writing on a budget
Kokuyo Campus B5, ruled
The Japanese school notebook, in B5, at a price that makes writing a hundred pages feel free.
#ad No live price right now. How this is funded
B5 is the size worth knowing about. It is bigger than A5 and smaller than A4, which turns out to be the right size for a page of longhand that you can still fit on a desk beside a laptop.
Kokuyo does not publish a weight for this notebook. What it does publish is the ruling, the sheet count and the fact that it lies flat.
At this price it is the notebook to use for drafts, practice and anything you would otherwise not write down at all.
| Size and ruling | B5, 6 mm ruledSource: Kokuyo Campus B5 (retail listing, read 2026-09-01) |
|---|---|
| Extent | 100 sheetsSource: Kokuyo Campus B5 (retail listing, read 2026-09-01) |
| Paper weight | Not published |
| Binding | Stitched, lies flat when openedSource: Kokuyo Campus B5 (retail listing, read 2026-09-01) |
What it does well
- Very cheap per page
- B5 is a genuinely useful longhand size
- Lies flat
What it does not
- No published paper weight
- Soft cover with no protection
- Ruling is tighter than most Western notebooks
Skip this if you write with a broad, wet nib — thin school paper is the worst case for show-through.
3. One book for a whole year
Stalogy 365 Days Notebook B6
A thin-paper daily notebook with a full year of dated grid pages in a book you can still carry.
#ad No live price right now. How this is funded
The idea is a single book for a year: thin paper, high page count, and a date grid printed at the top of every page so you do not have to write one.
Stalogy does not publish a weight, and the buyer feedback on its own listing is openly divided on bleed-through — some inks are fine, some are not. That division is what thin paper looks like when it is well made but still thin.
Ghosting is guaranteed. Whether it bothers you is a matter of taste, and some people like it.
| Format | B6, 365 Days NotebookSource: Stalogy 365 Days Note B6 (retail listing, read 2026-09-01) |
|---|---|
| Paper weight | Not published |
| Ruling | Grid, with date and time markers printed on each pageSource: Stalogy 365 Days Notebook, B6 slim, squared (retail listing, read 2026-09-01) |
| Also available | A5, A6 and B5 in the same formatSource: Stalogy 365 Days Notebook, A5 (retail listing, read 2026-09-01) |
What it does well
- A full year in one carryable book
- Date grid printed on every page
- Several sizes in the same format
What it does not
- No published paper weight
- Bleed-through reports are genuinely mixed
- Ghosting is unavoidable at this thickness
Skip this if show-through bothers you, or if you want to use a broad nib every day.
The compatibility trap
B-series paper does not fit A-series folders, sleeves, binders or document wallets. If your workflow involves filing loose pages, or handing them to someone who will file them, a B5 notebook is a size that nothing else you own accommodates.
That is the single practical reason B5 has not caught on outside Japan, and it is worth checking before you commit — a size you stop using because it will not file is a size you wasted money on.
What size does not tell you
How the paper behaves. A5 and B5 books from the same maker use the same stock, and an A5 notebook from a bad maker will bleed exactly as much as its A4 sibling. Size is an ergonomics decision; paper weight and sizing is the performance decision, and the two are entirely independent.
The same goes for ruling. Lined, dotted, squared and blank are available across essentially every size, and the choice between them changes how you work rather than how the ink behaves — see the dot grid roundup.
Buying advice, condensed
- Journaling or general writing: A5. It is the default for good reasons and almost everything is made in it.
- Long-form writing at a desk: B5, if you never need to file the pages.
- Carrying every day: B6 or A6. A hardcover in A5 is the largest most people carry comfortably.
- Drafting and diagrams: A4, and accept that it stays on the desk.
If you are buying a first notebook to go with a first pen, buy A5 and stop thinking about it — the start here guide covers the pairing that matters more.
Questions people actually ask
What size is an A5 notebook?
A5 is half a sheet of A4, folded along the long side. It is the default journal and notebook size — large enough for a full entry and small enough to carry comfortably.
Is B5 bigger than A5?
Yes. The B series sits between the A sizes, so B5 is larger than A5 and smaller than A4. It is the standard Japanese student notebook size.
What is the best notebook size for writing by hand?
B5 for longhand at a desk, because a wider page means fewer line breaks and longer uninterrupted strokes. A5 for a journal you carry. The trade with B5 is that it fits no A-series folder.
Does B5 paper fit in A4 folders?
No. The B and A series are different, so B5 pages do not fit A4 folders, sleeves or binders. Check that before committing if you file loose pages.
Does notebook size affect how ink behaves?
No. Bleed-through, ghosting and feathering are properties of the paper's weight, sizing and coating — an A5 and a B5 from the same maker use the same stock and behave identically.