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Common Stationery Sizes: A Practical Guide for Japanese Makers Selling to the U.S.

Last updated: August 2026

Size is the first filter an American stationery buyer applies. Planner users search by size before they look at your design. Card buyers check the envelope before they read the message. This guide gives you the exact millimetres, inches and market language for planners, notebooks, paper and cards.

Planner sizes

Planner people think in size first. If your sticker, insert or dashboard does not match the book they already own, they will scroll past. Here are the sizes that matter in the U.S. market.

SizeWho uses itProducts that fit
Pocket / Mini~90 × 140 mm · 3.5 × 5.5 inMinimalists, bag-conscious commuters, first-time planner buyers who want low commitment.Tiny sticker flakes, slim washi (5 mm), mini sticky notes, single-page dashboards.
A6 / Original105 × 148 mm · 4.1 × 5.8 inThe global default for daily one-page planners. Hobonichi Original, Midori MD A6, Traveler's Notebook passport inserts.A6 sticker sheets, half-page memo pads, bookmark markers, pocket folders, washi up to 15 mm.
B6125 × 176 mm · 4.9 × 6.9 inA middle ground growing fast in the U.S. — more writing room than A6 without A5 bulk. Popular with journalers.B6 sticker kits, wider washi (15–20 mm), dashboards, divider tabs, medium memo pads.
A5 / Cousin148 × 210 mm · 5.8 × 8.3 inHeavy planner users, students, professionals and decorators. Hobonichi Cousin, Kokuyo Jibun Techo, many academic planners.Full A5 sticker kits, wide washi (20–25 mm), laminated dashboards, full-page inserts, pen loops.
Weeks / Slim~94 × 187 mm · 3.7 × 7.4 inWallet-shaped weekly planners. Hobonichi Weeks, minimalists and professionals who carry in a jacket pocket.Narrow washi (5–10 mm), micro sticker sheets, slim pen loops, card-sized inserts, bookmark bands.
Personal / Bible~95 × 171 mm · 3.7 × 6.7 inRing-binder system users, especially Filofax and Kikki-K communities. Strong in Europe and Australia, niche but loyal in the U.S.Personal-size inserts, six-hole punched dashboards, top-loading pockets, snap-in sticky-note holders.

Paper and notebook sizes

Paper sizes shape shipping cost, printable templates and how your product feels in a buyer's hand. Keep this table next to your design files.

SizeNotes for sellers
A4210 × 297 mm · 8.3 × 11.7 inThe international office standard. Use it for letterhead, printables, art prints and packaging inserts sold outside the U.S.
Letter (US)216 × 279 mm · 8.5 × 11 inThe American default. If you sell printables to U.S. buyers, offer a letter-size PDF or they will ask for refunds.
A5148 × 210 mm · 5.8 × 8.3 inHalf of A4. The most common notebook and journal size in Japan and Europe; easy to ship flat.
B5176 × 250 mm · 6.9 × 9.8 inPopular for study notebooks and sketchbooks in Japan. Larger than A5 but still lighter than U.S. letter.
A6105 × 148 mm · 4.1 × 5.8 inPocket notebook size. Low shipping cost and a natural companion to A6 planners.
US Half-Letter140 × 216 mm · 5.5 × 8.5 inCommon in disc-bound and planner systems like Happy Planner and Arc. A useful printable size for U.S. buyers.

Card and envelope sizes

Cards are a high-margin, lightweight product, but sizing mistakes are expensive. A card that does not fit a standard envelope becomes a custom-order headache.

SizeNotes for sellers
Business card89 × 51 mm · 3.5 × 2 inU.S. standard. Japanese meishi are slightly larger at 91 × 55 mm, so always design to the market you are selling into.
Postcard (U.S.)140 × 89 mm · 5.5 × 3.5 inThe minimum size the USPS accepts. A strong format for stationery shops because it ships as a letter, not a parcel.
Postcard (JP)148 × 100 mm · 5.8 × 3.9 inThe Japanese postcard standard. If you sell to both markets, create two files rather than scaling one.
Greeting card (A2 folded)111 × 146 mm folded · 4.375 × 5.75 inA common U.S. greeting-card size. Cards are usually sold with matching envelopes; envelope size matters more than card size.
Square card (5 × 5 in)127 × 127 mm · 5 × 5 inPopular on Etsy for thank-you and occasion cards. Square envelopes often cost more to mail, so say so in shipping notes.

How to list sizes for U.S. buyers

These four habits will prevent the most common size-related complaints and returns.

Lead with the size the buyer searches for

American buyers rarely search 'B6' unless they are already deep in the community. They do search 'pocket planner,' 'A5 journal,' 'Hobonichi Cousin size,' and '5x7 card.' Put the everyday term in the title and the millimetres in the description.

Show the product inside the planner

A sticker sheet labelled 'A6' is abstract. A sticker sheet photographed on an open A6 page is proof. Proof converts.

Offer both metric and imperial in printables

If you sell downloadable inserts, make one file in A-series and one in U.S. letter or half-letter. Do not ask buyers to scale.

List envelope size with every card

A 5 × 7 in card needs an A7 envelope. Confusing envelope codes is one of the most common reasons stationery listings get bad reviews.

Frequently asked questions

What is the most popular planner size in the United States?

A5 and A6 are the most searched planner sizes overall. Within the Hobonichi ecosystem, A6 Original and Cousin (A5) dominate. For ring-bound systems, Personal and Pocket are common.

Should I list sizes in millimetres or inches on Etsy?

List both. Put the imperial measurement first in the title and body because most U.S. buyers think in inches, then add millimetres in parentheses for precision and international buyers.

What is the difference between A5 and B5 notebooks?

A5 is 148 × 210 mm; B5 is 176 × 250 mm. B5 gives more writing area and is popular for study logs and sketchbooks in Japan. A5 is more portable and fits more international covers.

Do U.S. buyers understand ISO paper sizes like A4 and A6?

A4 and A6 are widely understood because of printers and planners. A5 is understood by planner users. B-series sizes are less familiar outside stationery communities, so always include inch conversions.

What envelope size fits a 5 × 7 in greeting card?

An A7 envelope (5.25 × 7.25 in / 133 × 184 mm). The card is 5 × 7 in, but the envelope is slightly larger so the card slides in easily.

How do I avoid confusion when selling printables in both A4 and U.S. letter?

Create two separate PDFs. Label the filenames clearly, for example 'insert_a4.pdf' and 'insert_us_letter.pdf.' In the listing photos, show a mock-up of each page size and mention that no scaling is needed.

Price your paper goods with tariffs and shipping built in

The Cost & Price Studio helps you calculate true landed pricing for notebooks, cards, inserts and planner accessories sold to the U.S.

— Gin / Inari Stationery Strategy

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