What size suitcase should you bring to Japan?
Choose the case by the thresholds it has to cross, not by the number of days you are travelling. In Japan there are four of them, and each one moves your trip from easy to slightly awkward.
The four thresholds
115 cm around and 55 × 40 × 25 cm: the domestic flight cabin limit on ANA, JAL and Skymark. A 20-inch case clears it; a 22-inch case does not.
About 50 cm of height: the common medium locker, which is the size you will find free at almost any station. A case up to roughly 19 inches lies flat in one.
About 84 cm of height and 34 cm of depth: the large locker. It takes a case up to about 30 inches, but only if the depth with wheels stays under 34 cm — depth is what actually fails.
160 cm around: the Shinkansen oversized baggage threshold on the Tokaido, Sanyo, Kyushu and Nishi-Kyushu lines. Past it you need a reserved seat with an Oversized Baggage Area.
What each size means in practice
Up to 20 inches, about 51 × 36 × 23 cm: goes in the cabin on a domestic flight, fits a medium locker, needs no Shinkansen reservation. Nothing about this case is ever a problem. It holds about a week if you use a coin laundry, which Japan has on nearly every block.
21 to 24 inches: too big for the cabin, fits a large locker comfortably, no Shinkansen reservation. The sweet spot for a two-week trip.
25 to 30 inches: fits a large locker if the depth is under 34 cm, still under 160 cm around so no Shinkansen reservation, but you will be looking for the large cabinets rather than taking any free one.
Over 30 inches: past 160 cm around, so a Shinkansen reservation every time you move between cities, and only the extra-large lockers take it. Bring two smaller cases instead if you can.
Why depth matters more than people expect
Locker cabinets are narrow and deep: about 34 cm wide, 57 cm deep, and it is the height that changes between classes. A case goes in lying on its back, so its depth has to fit the cabinet width of 34 cm.
A hard-shell case measured at 29 cm can reach 34 cm once you count protruding wheels, an expansion zip left open and a soft cover. That is the difference between a locker taking it and not.
If you plan to use lockers, measure the depth with the wheels and buy on that number.
The case for two small cases
Two 22-inch cases hold more than one 30-inch case, weigh less each, both fit large lockers, neither needs a Shinkansen reservation, and either one can go on a train luggage rack. The cost is having two hands full.
For a family this is nearly always the right answer in Japan, where the constraint is space around you rather than the number of items.
Frequently asked questions
What is the best suitcase size for a two-week trip to Japan?
A 22 to 24-inch case. It fits a large coin locker, stays under the 160 cm Shinkansen threshold, and is small enough to get through a station at rush hour. Coin laundries are everywhere, so you need less than you think.
Is a 28-inch suitcase too big for Japan?
Not in the rules — at about 148 cm around it needs no Shinkansen reservation and it fits a large locker. It is awkward rather than forbidden: fewer lockers take it and stairs and rush-hour trains are harder.
What size fits in the cabin on a domestic flight?
55 × 40 × 25 cm and 115 cm around on ANA, JAL and Skymark, which in practice means a 20-inch case or smaller. A 22-inch case is over on both counts.
Should I bring one big case or two small ones?
Two small ones, almost always. They hold more between them, both fit large lockers, neither needs a Shinkansen reservation, and each is light enough to carry up a flight of stairs.
Check your own bag
All guides
Sources
- Keio Chika — Published coin locker internal dimensions and prices (Last checked 2026-09-09)
- JR East Smart Logistics — Multi Ecube coin locker sizes and fees (Last checked 2026-09-09)
- JR Central — Oversized baggage on the Shinkansen (Last checked 2026-09-09)
- ANA — Carry-on baggage size and rules, Japan domestic flights (Last checked 2026-09-09)
- Yamato Transport — Takkyubin size and weight table (Last checked 2026-09-09)
Last checked: 2026-09-09 — Rules and prices change. Coin locker dimensions in particular vary from station to station, so treat the sizes here as a guide and check the official page before you travel.