Children's shoe sizes

A shoe size is the length of a last, not an age and not a height. Below: a conversion from the insole, and a table from foot to size across all five systems.

Conversion from the insole

The most precise input: the insole IS what a size measures. This answer depends on nobody's table — a Paris-point size is by definition the last length divided by ⅔ cm.

Insole length

Table: foot, insole and size

The table steps by foot length rather than by size: the five systems step differently and incommensurably. What they share is the millimetre scale the foot itself was measured on.

Foot, cm	Insole, cm	EU	RU	US	UK	FR	IT	JP	KR
9.5	10.5	16	16	—	—	16	16	9.5	95
10	11	16.5	16.5	—	—	16.5	16.5	10.0	100
10.5	11.5	17.5	17.5	—	—	17.5	17.5	10.5	105
11	12	18	18	—	—	18	18	11.0	110
11.5	12.5	19	19	—	—	19	19	11.5	115
12	13	19.5	19.5	—	—	19.5	19.5	12.0	120
12.5	13.5	20.5	20.5	—	—	20.5	20.5	12.5	125
13	14	21	21	—	—	21	21	13.0	130
13.5	14.5	22	22	—	—	22	22	13.5	135
14	15	22.5	22.5	—	—	22.5	22.5	14.0	140
14.5	15.5	23.5	23.5	—	—	23.5	23.5	14.5	145
15	16	24	24	—	—	24	24	15.0	150
15.5	16.5	25	25	—	—	25	25	15.5	155
16	17	25.5	25.5	—	—	25.5	25.5	16.0	160
16.5	17.5	26.5	26.5	—	—	26.5	26.5	16.5	165
17	18	27	27	—	—	27	27	17.0	170
17.5	18.5	28	28	—	—	28	28	17.5	175
18	19	28.5	28.5	—	—	28.5	28.5	18.0	180
18.5	19.5	29.5	29.5	—	—	29.5	29.5	18.5	185
19	20	30	30	—	—	30	30	19.0	190
19.5	20.5	31	31	—	—	31	31	19.5	195
20	21	31.5	31.5	1	—	31.5	31.5	20.0	200
20.5	21.5	32.5	32.5	1.5	0.5	32.5	32.5	20.5	205
21	22	33	33	2	1	33	33	21.0	210
21.5	22.5	34	34	2.5	1.5	34	34	21.5	215
22	23	34.5	34.5	3	2	34.5	34.5	22.0	220
22.5	23.5	35.5	35.5	4	3	35.5	35.5	22.5	225

Where these numbers come from

This table is copied from nobody: it is computed from the unit definitions. A Paris point is ⅔ cm, a barleycorn is ⅓ inch, Mondopoint is foot length in millimetres per ISO 9407. So check it against the definition, not against someone else's table.

The allowance is the one number here without a strict source, and we say so out loud. The literature cites 10–15 mm of toe room; children's footwear adds a growth allowance on top, and manufacturers print it differently. That is why the foot under the insole is shown as a range: a single number would pass a convention off as a fact.

The US and UK columns are ONE adult ladder, as on every other shoe page here (`ADR-022`). Children's footwear in those countries runs its own scale with its own 13 → 1 rollover, and we do not model it: where our formula has nothing to say there is a dash, not an invented number.