Journal & Notebook Sizes Guide: A4, A5, B5, B6, A6, Regular & Pocket

Journal and notebook sizes follow two standards. The ISO 216 A-series runs A4 (210 × 297 mm / 8.3 × 11.7 in), A5 (148 × 210 mm / 5.8 × 8.3 in), A6 (105 × 148 mm / 4.1 × 5.8 in) and A7 (74 × 105 mm / 2.9 × 4.1 in). The B-series covers B5 (176 × 250 mm ISO; 182 × 257 mm JIS) and B6 (125 × 176 mm). Alongside these sit formats brands made standard anyway: Traveler's Notebook Regular (110 × 210 mm), Pocket / Field Notes (89 × 140 mm), Passport (90 × 125 mm), and US Composition (190 × 247 mm).

A5 is the most-used size for journaling and planning. B6 is the sweet spot for portable daily use. Regular is the traveler's notebook format.

One thing almost every size chart leaves out: a refillable leather cover is always slightly larger than the paper inside it. The chart below gives both numbers, because that difference is what decides whether your notebook actually fits.

That is the technical answer. Here is the useful one.

Choosing a leather journal size sounds easy until the tabs start multiplying in your brain. A5 looks sensible. Pocket Size looks cute. Regular is tall, slim, and travel-ready. A4 offers the most page space of any size in this guide.

So here is the honest version: you are not only choosing a journal size. You are choosing what kind of life your leather journal needs to carry.

At Asperaria, we make handmade refillable leather journals for people who use paper in very different ways. Some write long entries. Some rapid-log tiny thoughts between errands. Some sketch. Some plan. Some glue in movie tickets, cafe receipts, stickers, photo strips, and the little paper scraps that somehow hold the whole day together. Some people want one clean journal. Some people want an analog second brain with three inserts, a pocket, a pen loop, and absolutely no apologies.

This journal size guide will help you choose between A4, A5, B6, A6, Field Notes-compatible, Pocket Size, B5, and Regular Size journals and notebooks so you can pick confidently in a few minutes.

Quick Answer: Which Journal Size Should You Choose?

If you want one safe first choice, choose A5. It has enough room for journaling, planning, notes, sketching, memory keeping, and daily life without becoming a desk-only object.

If your journal has a more specific job, start here:

First: A Journal Is a Setup, Not Just a Size

The old way to choose a notebook was simple: pick a size, buy the notebook, and hope it matches how you actually write.

A refillable leather journal works differently. The cover can stay with you while the inside changes. You can keep one insert for daily journaling, another for planning, another for sketches, another for travel memories, and a pocket for cards, receipts, stickers, ticket stubs, notes from friends, or the tiny mysterious paper that was clearly important three weeks ago.

That is why size matters. Not only because of handwriting or page space, but because of setup capacity:

• One insert: simple, light, clean, easy to carry.
• Two inserts: planner plus journal, notes plus sketches, work plus personal.
• Three or more inserts: a full analog system for planning, memory keeping, commonplacing, projects, and everyday carry.
• Pockets or inserts: useful if you collect loose things: cards, receipts, stickers, stamps, tickets, photos, lists, and small keepsakes.

If you want one place for planning, journaling, and daily notes instead of several separate apps or notebooks, a refillable leather journal is built for exactly that.

Asperaria Journal & Notebook Sizes Chart

These are the paper insert sizes that fit each format, plus the Asperaria leather cover measurements from our product pages. Always check the individual product page before ordering if you already have a favorite notebook insert — paper brands can vary by a few millimeters, and a few millimeters can be the difference between a notebook that fits and one that does not.

Where these sizes come from, in short: ISO 216 defines the A and B paper families used worldwide. Japan also uses JIS B sizes (slightly larger than ISO B). Traveler's Notebook Regular, Field Notes / Pocket, Passport, and US Composition became de facto standards because people kept buying them — not because a committee voted.

Important note: size names like A4, A5, A6, B5, B6, Regular, Pocket, and Field Notes-compatible are useful shortcuts, but the exact fit depends on the cover design, insert thickness, and the notebook brand you want to use. If you use Moleskine, Leuchtturm1917, Field Notes, Traveler's Company, Midori, Hobonichi, or any third-party refill, compare measurements before ordering. If your favorite notebook is unusual, we can discuss a personalized or custom setup.

Asperaria Leather Insert Sizes

The rule is short enough to remember: covers are bigger than the paper, inserts are the same size as the paper. Our leather inserts — zip pockets, card holders, organizer pieces — are cut to the paper footprint for that format, so they stack on the elastics alongside your notebooks instead of sticking out like something that wandered in from a different setup.

What Size Is an A5 Notebook? (And Every Other Format)

Direct answers for the size questions people actually search. Paper dimensions first; Asperaria cover size second where we make that format.

What size is an A5 notebook?

A5 is 148 × 210 mm (5.8 × 8.3 in / 14.8 × 21 cm) — exactly half an A4 sheet. It is the most common journal and planner size. An Asperaria A5 leather cover measures 6 × 8.5 in (15.2 × 21.6 cm), so the paper sits inside without bowing.

What size is an A6 notebook?

A6 is 105 × 148 mm (4.1 × 5.8 in / 10.5 × 14.8 cm) — half of A5, a quarter of A4. An Asperaria A6 leather cover measures 4.5 × 6 in (11.4 × 15.2 cm).

What size is a B6 notebook?

B6 is 125 × 176 mm (4.9 × 6.9 in / 12.5 × 17.6 cm). It sits between A5 and A6 for portable daily writing. An Asperaria B6 leather cover measures 5.2 × 7.2 in (13.2 × 18.3 cm).

What size is a B5 notebook?

ISO B5 is 176 × 250 mm (6.9 × 9.8 in). JIS B5 is slightly larger at 182 × 257 mm (7.2 × 10.1 in). An Asperaria B5 leather cover measures 7.2 × 10.2 in (18.3 × 25.9 cm) — built for ISO-style B5 inserts and similar large notebooks.

What size is an A4 notebook?

A4 is 210 × 297 mm (8.3 × 11.7 in / 21 × 29.7 cm). An Asperaria A4 leather cover measures 8.9 × 12.6 in (22.6 × 32 cm).

What size is an A7 notebook?

A7 is 74 × 105 mm (2.9 × 4.1 in). It is a common mini notepad size. Asperaria does not currently sell a dedicated A7 cover; for tiny carry, look at Pocket Size or Field Notes-compatible instead.

What size is a pocket notebook?

"Pocket notebook" usually means either Field Notes-style 3.5 × 5.5 in (89 × 140 mm) paper, or a brand's own pocket format. Asperaria Pocket Size covers measure 4.3 × 5.4 in (10.9 × 13.7 cm) and take Pocket Size paper refills at 4 × 5.1 in (10.2 × 13 cm). Field Notes-compatible covers measure 3.8 × 5.8 in (9.7 × 14.7 cm) for standard 3.5 × 5.5 in notebooks.

What size is a Traveler's Notebook (Regular)?

Traveler's Notebook Regular inserts are 110 × 210 mm (4.3 × 8.3 in). An Asperaria Regular Size leather cover measures 4.8 × 8.8 in (12.2 × 22.4 cm), and our own Regular leather inserts are 4.5 × 8.5 in (11.4 × 21.6 cm).

What size is a composition notebook?

A US composition notebook is typically about 190 × 247 mm (7.5 × 9.75 in). That is close to B5 in spirit, but not identical — measure before assuming fit. For large desk or study pages in an Asperaria cover, start with B5 or A4.

What are standard notebook sizes?

The standard notebook sizes are A4 (210 × 297 mm), B5 (176 × 250 mm ISO), A5 (148 × 210 mm), B6 (125 × 176 mm) and A6 (105 × 148 mm), plus three non-ISO formats that became standards anyway: Pocket / Field Notes (89 × 140 mm), Traveler's Notebook Regular (110 × 210 mm) and Passport (90 × 125 mm). A5 is the default for journals and planners; A4 and B5 are the school and office defaults.

Are notebooks usually A4 or A5?

It depends on the job. School and office notebooks are usually A4 or B5, because they need to match printed handouts. Journals, planners and personal notebooks are usually A5 or smaller — A5 is the single most common journal size, and A6 and B6 take over when portability matters more than page space.

Is a normal notebook A5 or B5?

Both, depending on where you are. In most of Europe a "normal" notebook is A5 or A4. In Japan, B5 is the standard school size. In the US the closest everyday equivalent is the composition notebook at roughly 190 × 247 mm, which sits near B5. For journaling specifically, A5 is the normal one.

Which is bigger, A5, A4 or B5?

A4 is the largest at 210 × 297 mm. B5 comes next at 176 × 250 mm. A5 is the smallest of the three at 148 × 210 mm. B5 sits neatly between A4 and A5, which is exactly what the B-series was designed to do.

How Many Notebooks Fit in One Cover?

Most Asperaria covers use elastic bands to hold replaceable inserts. How many you can stack depends on the model (many use 2, 3, or 5 elastics; some offer 6) and how thick each insert is. Typical spine capacity on our modular covers:

Check the product page for the default elastic count on the model you want, and remember that a thick sketchbook or a zipper pouch eats far more spine than a slim memo booklet. One warning from experience: just because six will fit does not mean six is a good idea. Somewhere past four you stop carrying a journal and start carrying a small book about yourself.

Choose by What You Actually Do

Measurements are useful. Your habits are more useful. Here is the no-drama way to choose.

Size-by-Size Guide

A4 Leather Journals: Big Pages, Big Plans

A4 leather journals are for people who need space. They are excellent for sketching, tattoo design development, study notes, visual planning, large project layouts, music sheets, and desk journaling.

The tradeoff is portability. A4 is not trying to sneak into a tiny bag. A4 is the journal you keep on a desk, in a studio, in a work bag, or anywhere you can open a big page and actually think.

Choose A4 if your work gets cramped in smaller notebooks. Skip A4 if your main goal is everyday carry.

B5 Leather Journals: Desk-Scale Without Going Full A4

B5 leather journals sit between A5 and A4. The cover measures 7.2 × 10.2 in (18.3 × 25.9 cm) and takes ISO B5 notebooks at 176 × 250 mm, plus most sketchbooks and study pads in that family.

B5 is the size people usually arrive at after owning the other two. A5 fills up embarrassingly fast once you start drawing. A4 stops fitting in the bag you actually own, as opposed to the bag you imagined yourself carrying. B5 is the compromise that stops feeling like one after about a week.

Choose B5 if A5 feels cramped for sketching or lecture notes but A4 is more book than you want to carry.

A5 Leather Journals: The Best All-Around Size

A5 leather journals are the safest first choice because they work for almost everything: daily journaling, planning, work notes, study, memory keeping, commonplacing, sketching, and creative projects.

A5 is especially good if you want a refillable journal setup with multiple inserts, inner pockets, a pen loop, personalization, or a mix of planning and journaling in one cover.

Choose A5 if you want one main journal. It offers the best balance of writing space and portability of any size in this lineup.

B6 Leather Journals: Compact, But Still Comfortable

B6 leather journals are for people who want something smaller than A5 but more generous than A6. B6 is great for daily journaling, commonplacing, reading notes, compact planning, and carrying a personal journal without feeling like you packed a textbook.

B6 is also a good choice if you like the idea of a main journal but know A5 feels a little too big for your actual bag, actual desk, or actual patience.

Choose B6 if you want portable pages that still let you write like a person with thoughts longer than a grocery list.

A6 Leather Journals: Small, Useful, Easy to Keep Close

A6 leather journals are compact without being uselessly tiny. They work well for quick daily entries, gratitude notes, rapid logs, travel notes, task lists, pocket-ish carry, and small sketches.

A6 is not the best size for long essays, full planning spreads, or large art pages. It is excellent when you want something close, quick, and low-pressure.

Choose A6 if you want a journal that says, "Just write the thing down." Sometimes that is the whole job.

Field Notes-Compatible Leather Covers: Tiny Journal, Big Utility

Field Notes-compatible leather covers are made for standard 3.5 x 5.5 in pocket notebooks. Use this size for quick capture, field notes, measurements, lists, names, observations, travel details, and ideas that do not politely wait until you get home.

This size is also good as a secondary journal: one small notebook for the street, one larger journal for the desk. That split works especially well if you like to catch ideas quickly and sort them later.

We use "Field Notes-compatible" as a size reference only. It does not imply an official affiliation with the Field Notes brand.

Pocket Size Leather Journals: The Backup Brain

Pocket Size leather journals are for fast capture: tiny notes, small lists, client details, song lines, mini sketches, measurements, addresses, recommendations, and the thought you want to make sure you do not forget.

Pocket Size is not for huge layouts or long daily pages. It is for keeping paper close enough that using it feels easier than unlocking your phone.

Choose Pocket Size if the honest alternative is typing the thought into your phone and never opening that note again.

Regular Size Leather Journals: Tall, Slim, and Built for Setups

Regular Size leather journals are tall, slim, and especially good for traveler's notebook-style setups. Choose Regular Size for lists, itineraries, daily logs, setlists, reading notes, narrow planning pages, travel journaling, and a combined planner-journal system.

Regular Size feels less like an open table and more like a path. It keeps writing moving forward. That makes it great for people who think in sequences: morning notes, running tasks, trip logs, habit check-ins, project lists, and anything else you need to track before it slips your mind.

Choose Regular Size if your life mostly happens in lists.

How to Build a Journal Setup That You Will Actually Use

The best journal setup is not the prettiest one on day one. It is the one you keep reaching for on a normal Tuesday when nothing cinematic is happening.

Here are a few setup ideas:

If you are new to refillable journals, start simple. One cover. One or two inserts. One pen. Maybe a pocket if you collect loose stuff. You can always add more later, once you know how you actually use it.

What If You Pick the Wrong Size?

That is a normal part of finding a setup that works for you.

False starts are normal. You may try Pocket Size and realize you want more room. You may try A5 and realize you only carry it when you are not in a rush. You may start with a blank insert and discover you need dot grid. You may build a full planner setup and later strip it down to one insert and a pen.

That is not failure. That is how a personal system gets personal.

The good part of a refillable leather journal is that the cover can keep going while the inside changes. Swap inserts. Try a different paper style. Move planning into one booklet and journaling into another. Add a leather journal insert when you need pockets. Keep what works. Retire what does not. No ceremony required.

Left-Handed Journaling and Refillable Covers

If you write left-handed, the format that matters most is how the book opens — not a special fountain-pen paper recipe. A refillable leather cover with center elastics opens flat and lets pages turn either way, so your hand is less likely to fight a stiff right-bound spine. Slimmer sizes (B6, A6, Regular) can also feel easier to stabilize while writing. Choose the page size you actually fill; the cover should stay out of the way.

A4 vs A5 vs A6: The Simple Difference

A4, A5, and A6 are useful size families, but real-world notebook brands and leather covers can vary. Think of them like this:

• A4: best when page space matters more than portability.
• A5: best when you want one main journal for writing, planning, and creative life.
• A6: best when you want compact carry and shorter entries.

If you already have a specific insert or notebook, measure it. If you are choosing an Asperaria journal from scratch, start with your use case first, then choose the size.

Best Journal Size by Personality of Use

Different journaling styles call for different formats. Here is how to match yours.

Will My Moleskine, Leuchtturm, or Hobonichi Fit?

Often yes for the matching paper family — but brand notebooks are not identical. Use this as a starting map, then compare your notebook's exact width × height × thickness to the Asperaria cover size above.

If the fit is unusual, email us the measurements. Custom covers exist for a reason.

How Asperaria Refillable Leather Journals Work

Asperaria journals are handmade leather covers designed for refillable journal and notebook systems. Most designs use elastic bands to hold replaceable inserts, so you can keep the leather cover and change the paper when it is full.

Depending on the model, an Asperaria journal may include two, three, five, or six elastics, inner pockets, zipper storage, pen loops, wrap closures, leather inserts, or personalization. Some people keep it minimal. Some people build a whole modular setup. Both are correct. The point is to build a cover you will actually use every day.

Start with all leather journals if you want to compare every format. If you already know your size, go straight to A5, A6, A4, B5, B6, Field Notes-compatible, Pocket Size, or Regular Size.

If you want the cover to carry more than paper, browse leather journal inserts for pockets and organizer pieces. If you want initials, a name, or a gift-ready piece, start with personalized leather journals.

Still Not Sure? Here Is the Honest Advice

If you have read this far and still cannot decide, that is normal, and it matters less than it feels like it does right now.

Buy A5. It is the size most people land on, it works for nearly every setup, and if it turns out to be the wrong call you will know within two weeks — and the cover will still be worth owning. If it is a gift, add personalization. It makes a safe choice look like a considered one, which, to be fair, it is.

The only decision worth thinking hard about is the one you cannot undo later: the color. Paper, layout, how many inserts, whether you journal every morning or in guilty bursts every three weeks — all of that is swappable. That is the entire point of a refillable cover.

And if your favorite notebook is an odd size, send us the measurements. That is what the custom option is there for.

FAQ

What is the best journal size for beginners?

A5 is usually the best first journal size because it gives enough room for writing, planning, notes, and creative pages while still being portable. If you want a smaller everyday carry journal, choose A6, Pocket Size, or Field Notes-compatible instead.

What is the best size for a refillable leather journal?

A5 is the most versatile size for a refillable leather journal. Regular Size is best for a tall slim traveler's notebook-style setup. A6, Pocket Size, and Field Notes-compatible covers are better for compact carry. A4 is best for desk and studio use.

What journal size is best for everyday carry?

A6, Pocket Size, Field Notes-compatible, and Regular Size are the best choices for everyday carry. Choose the smallest size if you mainly capture quick notes. Choose Regular Size if you want a portable setup with planning and journaling together.

What is the best journal size for memory keeping?

A5 is the strongest choice for memory keeping because it gives room for writing, photos, tickets, stickers, receipts, and ephemera. B6 and Regular Size also work well if you want something more portable.

What is the best journal size for a planner and journal in one?

A5, B6, and Regular Size work best for a combined planner and journal. A5 gives the most flexible page space, B6 is more compact, and Regular Size is ideal for tall weekly layouts, lists, and multi-insert systems.

What is the best journal size for sketching?

A4 is best for larger sketches, visual planning, and studio work. B5 is the middle ground, and A5 is better if you want a portable sketch journal. A6, Pocket Size, and Field Notes-compatible covers are best for quick doodles, thumbnails, and ideas on the go.

Is A5 or A6 better for journaling?

A5 is better for longer entries, planning spreads, memory keeping, and one-main-journal setups. A6 is better for short entries, travel notes, quick lists, and everyday carry.

Is B6 a good journal size?

Yes. B6 is a strong middle size between A5 and A6. It is portable but still comfortable for real writing, commonplacing, reading notes, and compact planning.

What size is Field Notes-compatible?

Field Notes-compatible covers are made for standard 3.5 x 5.5 in pocket notebooks. This is a size compatibility reference, not an official affiliation with the Field Notes brand.

Can I use Moleskine, Leuchtturm1917, or other notebook inserts?

Sometimes, but always compare the exact notebook measurements with the product page before ordering. Notebook brands vary by size, thickness, binding, and cover stiffness. If the fit is unusual, contact us with the measurements.

Are Asperaria leather journals refillable?

Yes. Most Asperaria leather journals are refillable leather covers designed to hold replaceable notebook inserts with elastic bands. You can fill the paper, replace the insert, and keep using the same leather cover.

Can Asperaria make a custom journal size?

Yes. If a standard size does not fit your favorite notebook or your ideal setup, contact us with the measurements and intended use. We can discuss a custom leather journal cover made for your needs.

Is A5 half of A4?

Yes. An A5 sheet is exactly half an A4 sheet: A4 is 210 × 297 mm, A5 is 148 × 210 mm. Fold A4 in half along the long edge and you get A5.

What is the difference between ISO B5 and JIS B5?

ISO B5 is 176 × 250 mm. JIS B5 (common in Japanese planners) is 182 × 257 mm — a little larger. If you use a Japanese B5 planner, measure it against the Asperaria B5 cover (7.2 × 10.2 in / 18.3 × 25.9 cm) before ordering.

What size notebook fits in a jacket pocket?

Field Notes-compatible (3.5 × 5.5 in paper) and Asperaria Pocket Size are the usual jacket-pocket candidates. A6 can work in a larger coat pocket. A5 usually needs a bag.

Which size is closest to US Letter?

US Letter is 8.5 × 11 in (216 × 279 mm). Nothing in the A-series matches it exactly. A4 is taller and slightly narrower; for desk work in an Asperaria cover, A4 is still the closest everyday option.

Is B6 bigger than A6?

Yes. B6 paper is 125 × 176 mm; A6 is 105 × 148 mm. B6 gives more writing room while staying more portable than A5.

What size are Asperaria leather inserts?

Leather inserts are cut to the same footprint as the paper for that format, so they sit flush on the elastics: A4 8.3 × 11.7 in, B5 6.9 × 9.8 in, A5 5.8 × 8.3 in, Regular 4.5 × 8.5 in, B6 4.9 × 6.9 in, A6 4.1 × 5.8 in, Field Notes 3.5 × 5.5 in, Pocket Size 4 × 5.1 in.

How many notebooks fit in one Asperaria cover?

It depends on elastic count and insert thickness. Many covers ship with 3 or 5 elastics; some models offer 2 or 6. See the spine-width table above, and always check the product page for that model.