Country chart — Europe (ISO)

EU ring size chart

The European system is the simplest of all: the size IS the measurement. Under ISO 8653:2016, an EU size is the inner circumference of the ring in millimetres. EU 52 means 52 mm around the inside — no lookup table needed to understand it.

How the EU / ISO system works

Size = circumference in mm

ISO 8653:2016 defines standard ring sizes by inner circumference in millimetres. A paper strip measurement in millimetres is already an EU size, with no conversion at all.

Used across continental Europe

Austria, France, Belgium and the Nordic countries use ISO sizes, among others. France uses the same circumference number; Germany is different — see below.

Diameter is circumference ÷ π

EU 52 → diameter 52 ÷ π = 16.55 mm. The table below lists that diameter for every ISO size from 44 to 72, rounded to 0.1 mm.

EU / ISO chart — 44 to 72

EU / ISO ring size chart, sizes 44 to 72, with inner diameters.
EU / ISO size (circumference, mm)	Inner diameter
44	14.0 mm
45	14.3 mm
46	14.6 mm
47	15.0 mm
48	15.3 mm
49	15.6 mm
50	15.9 mm
51	16.2 mm
52	16.6 mm
53	16.9 mm
54	17.2 mm
55	17.5 mm
56	17.8 mm
57	18.1 mm
58	18.5 mm
59	18.8 mm
60	19.1 mm
61	19.4 mm
62	19.7 mm
63	20.1 mm
64	20.4 mm
65	20.7 mm
66	21.0 mm
67	21.3 mm
68	21.6 mm
69	22.0 mm
70	22.3 mm
71	22.6 mm
72	22.9 mm

France and Germany — not the same number

France: same as EU

French sizes are the same circumference number as EU / ISO sizes. A French 52 is an EU 52.

Germany: diameter, not circumference

German sizes are the inner diameter in millimetres (for example 16.5 or 17). Germany is therefore not given a separate column in the unified chart — the diameter column already is the German size. Do not confuse a German 17 (17 mm across) with an EU 17 (which does not exist).

Conversion examples

EU 52 → US 6 (approx.)

Diameter 16.55 mm; nearest US row is US 6 (16.51 mm). The 0.04 mm gap is EU rounding, not an error.

EU 54 → US 7 (approx.)

Diameter 17.19 mm; nearest US row is US 7 (17.32 mm).

EU 57 → US 8 (approx.)

Diameter 18.14 mm; nearest US row is US 8 (18.14 mm) — an exact row match this time.

Note: EU 72 is in the ISO table but outside the US 3–13.5 chart range, so the converter shows its diameter and circumference but no US / UK row equivalent. EU 71 still maps to US 13.5. An unavailable conversion, explained — not a fabricated label.

Original references

Wikipedia — Ring size (ISO 8653:2016 circumference table)

ISO 8653:2016 itself is a paid standard; the circumference table above is the standard's published table as reproduced in the Wikipedia reference, cross-checked by diameter = circumference ÷ π for every row. The definition (size = inner circumference in mm) is not in dispute across sources.

Related guides

International ring size chart
All systems on one table.
US ring size chart
The number system EU sizes convert to.
Ring size converter
Convert an EU size to any other system.