Japan to US Women's Shoe Size Conversion
| Japan (cm) | US |
|---|---|
| 22 | 5 |
| 22.5 | 5.5 |
| 23 | 6 |
| 23.5 | 6.5 |
| 24 | 7 |
| 24.5 | 7.5 |
| 25 | 8 |
| 25.5 | 8.5 |
| 26 | 9 |
| 26.5 | 9.5 |
| 27 | 10 |
Sizing conventions vary by brand and by cut — this table shows the standard published conversion. Always check the garment's own size chart when one is available. See how these tables are compiled.
Starting from a real measurement, not a code
A Japanese size like 24 or 24.5 is the actual foot length in centimetres the shoe is built for, unlike the US scale, which climbs in arbitrary half-size steps with no fixed unit underneath. Converting JP to US means translating a genuine length measurement into an approximate US number — the opposite direction is far less precise, since the US size never encoded a length to begin with.
Because of that, the same JP size can convert to slightly different US numbers depending on which brand's US-size chart you're using; some US brands calibrate their half sizes a touch differently against actual foot length than others do, so a JP 24 might land at a US 7 on one chart and a US 6.5 on another.
US lasts run wider than Japanese ones
Japanese women's lasts, especially from Japanese domestic brands, tend to be cut narrower through the forefoot than typical US lasts. Someone used to a snug Japanese fit who converts straight to the 'equivalent' US size in an American brand often finds noticeably more room across the ball of the foot — not a sizing mistake, just a different last shape at the same converted length.
The more reliable path
Your JP size already IS your foot length in centimetres, which is a genuine advantage over converting from a coded US or UK size — skip the size-number lookup entirely and hand a US retailer the centimetre figure directly if their site accepts it, since that removes a rounding step the JP-to-US table itself has to introduce.
US brands rarely publish a JP column
Unlike Japanese and Korean retailers, who commonly print several regional size columns on one chart because their products ship across Asia, most US brands only publish US sizing plus, at best, a cm length column — a direct JP-to-US size-number lookup usually isn't available on the US retailer's own page at all. That's actually a reason to lean on your JP-derived foot length in inches rather than hunting for a JP column that most American brands simply don't carry.
What the US side of this conversion doesn’t tell you
A converted US size says nothing about width, and Japanese lasts are commonly built narrower through the midfoot than a typical US last — a foot that’s wide relative to its length often needs to size up half a US size beyond what the straight length conversion suggests.
Frequently asked questions
Does JP 24 always convert to the same US size?
Not exactly — different US brands calibrate their half-size steps against actual foot length slightly differently, so JP 24 might land at US 7 on one brand's chart and US 6.5 on another's.
Why does a US shoe in my converted size feel roomier than my Japanese shoe?
Think of it as buying the right length in a different-shaped box — a domestic Japanese last is built narrower through the forefoot, so an American shoe at your converted length has extra volume there that your foot simply isn't used to feeling.
Is it more accurate to convert my JP size or just measure my foot directly?
Measuring directly is more accurate — your JP size already reflects your foot length in centimetres, so converting that length to inches and checking the US brand's own chart skips an unnecessary rounding step.
Will a US brand's website show me a JP size directly?
Usually not — most US brands publish only US sizing and sometimes a cm length column, unlike Asian retailers who often list several regional columns at once. Converting your own foot length is more reliable than searching for a JP column that likely isn't there.