Package size & weight
3 sides total—
Cheapest ways to ship
Enter the three sides and the weight to compare shipping methods.
Rates are flat nationwide, Rates are a guide（after the Oct 2024 revision (estimate)）。
When you ship an item from a Japanese flea-market app (Mercari, Rakuma, Yahoo! Flea Market) or a small shop, figuring out the cheapest way to send it for a given size and weight is a chore you redo every time. This tool compares Japan's flat-rate shipping options at once: just enter the parcel's three sides (length, width, thickness in cm) and its weight (g or kg), and it lists every method the parcel fits, sorted from cheapest, with the lowest one highlighted. It covers Japan Post's flat-rate products (standard and non-standard letters, Smart Letter, Click Post, Letter Pack Light / Plus) and the anonymous flea-market services Raku-Raku Mercari Bin and Yu-Yu Mercari Bin (Nekoposu, Yu-Packet, Yu-Packet Post, Yu-Packet Plus, Takkyubin Compact, Takkyubin and Yu-Pack). Each method has limits on thickness, total of the three sides, and weight; methods your parcel doesn't fit are greyed out with the reason ("too thick", "too heavy", "too big") so it's obvious why. Methods that require a dedicated box, such as Takkyubin Compact and Yu-Packet Plus, are compared as the postage plus the box fee. Rates are a guide based on the figures in force after Japan Post's October 2024 revision, and each method links to its official page since prices can change. Over-the-counter Takkyubin and Yu-Pack are priced by region (origin to destination) and can't be reduced to a single number from size alone, so this tool focuses on flat-rate methods plus the equivalent flat-rate Mercari size services. The dimensions and weight you enter are computed only inside your browser and are never sent to any server.
How to use
- Enter the parcel's three sides (length, width, thickness) in cm and its weight in g or kg. Pick a common item from "Example" to fill the fields fast.
- The methods your parcel fits appear sorted from cheapest, with "Cheapest" on the lowest one. Methods that need a box show the total including the box fee.
- Methods that don't fit are greyed out with the reason. Open each method's "Official" link to confirm the latest rate and size conditions.
FAQ
Are the size and weight I enter sent to a server?
No. Choosing eligible methods and computing the postage both happen entirely in your browser; the dimensions and weight you enter are never uploaded, stored, or transmitted. It works fully locally.
Why don't I see prices for ordinary counter Takkyubin or Yu-Pack?
At-the-counter Takkyubin and Yu-Pack are priced by the combination of origin and destination region, so size and weight alone don't pin down a single price. This tool focuses on methods that cost the same to anywhere in Japan (flat rate). For size-based parcels, it includes the flat-rate Mercari versions — Takkyubin via Raku-Raku Mercari Bin and Yu-Pack via Yu-Yu Mercari Bin.
Which side should I enter as the thickness?
The order of the three sides doesn't matter. The tool sorts them and treats the smallest one as the thickness, checking it against each method's thickness limit (2.5 cm for Nekoposu, 3 cm for Click Post and Yu-Packet, and so on). For a soft item you can flatten in an envelope, enter the thickness after flattening for a realistic result.
Do the prices include the box fee for Takkyubin Compact and Yu-Packet Plus?
Yes. Methods that need a dedicated box are compared and shown as the postage plus the box fee (¥70 for Takkyubin Compact, ¥65 for Yu-Packet Plus), with the breakdown noted underneath.
As of when are these prices?
They are a guide based on the figures in force after Japan Post's October 2024 revision. Rates can change, so check each method's "Official" link for the current price and size conditions before you ship.