Ring size by finger
Ring-size charts map inner diameter or circumference to a size label. They do not assume a particular finger and cannot provide a reliable offset from one finger to another.
What the chart measures
- US, UK, EU and other labels describe ring dimensions, not finger identity.
- Index, middle, ring, little finger, thumb and toe can each require a different measurement.
- The two hands can also differ, so there is no safe universal offset.
Measure the exact finger and hand
- Measure where the ring will sit and also check the knuckle.
- Repeat the measurement at a normal room temperature.
- Use the larger consistent measurement if two careful readings differ slightly.
- Convert that measured diameter or circumference below.
Convert your measurement
Input: 17.3 mm
Your size is US 7 (UK N½, EU 54).
Measurement check Exact table match
Measurement check Inner diameter from a ring that already fits is usually the strongest home input. Re-measure across the widest inner points and check wide-band fit if needed.
- US
- 7
- UK
- N½
- EU / ISO
- 54
- Japan
- 14
- CH / IT / ES
- 14
- Inner diameter, millimetres
- 17.32
- Circ mm
- 54.4
Why this size?
Your input maps to US 7 — UK N½, EU 54, JP 14, Ø 17.32 mm.
Calculated dimensions are rounded chart values, not a measured accuracy guarantee. Ruler placement, print scale, screen calibration and the finger can change the result. Confirm with a physical sizer before ordering.
More options
Choose the fit problem and get the safest next step before resizing, replacing or buying another ring.
Wide band or comfort-fit Too loose or spinning Non-resizable or brand ring Smart-ring fit issue
| US | UK | EU | JP | CH | Inner diameter, millimetres | Circ mm |
|---|---|---|---|---|---|---|
| 3 | F½ | 44 | 4 | 4 | 14.07 | 44.2 |
| 3.5 | G½ | 45 | 5 | 5 | 14.48 | 45.5 |
| 4 | H½ | 47 | 7 | 7 | 14.88 | 46.8 |
| 4.5 | I½ | 48 | 8 | 8 | 15.29 | 48.0 |
| 5 | J½ | 49 | 9 | 9 | 15.70 | 49.3 |
| 5.5 | K½ | 51 | 10 | 11 | 16.10 | 50.6 |
| 6 | L½ | 52 | 12 | 12 | 16.51 | 51.9 |
| 6.5 | M½ | 53 | 13 | 13 | 16.92 | 53.1 |
| 7 | N½ | 54 | 14 | 14 | 17.32 | 54.4 |
| 7.5 | O½ | 56 | 15 | 16 | 17.73 | 55.7 |
| 8 | P½ | 57 | 16 | 17 | 18.14 | 57.0 |
| 8.5 | Q½ | 58 | 17 | 18 | 18.54 | 58.3 |
| 9 | R½ | 60 | 18 | 20 | 18.95 | 59.5 |
| 9.5 | S½ | 61 | 19 | 21 | 19.35 | 60.8 |
| 10 | T½ | 62 | 20 | 22 | 19.76 | 62.1 |
| 10.5 | U½ | 63 | 22 | 23 | 20.17 | 63.4 |
| 11 | V½ | 65 | 23 | 25 | 20.57 | 64.6 |
| 11.5 | W½ | 66 | 24 | 26 | 20.98 | 65.9 |
| 12 | Y | 67 | 25 | 27 | 21.39 | 67.2 |
| 12.5 | Z | 68 | 26 | 28 | 21.79 | 68.5 |
| 13 | Z½ | 70 | 27 | 30 | 22.20 | 69.7 |
Frequently asked questions
Does a ring-size chart assume the ring finger?
No. A size chart maps ring dimensions to labels. The wearer must measure the exact finger and hand.
Can I calculate a thumb or little-finger size from my ring finger?
Not reliably. Differences vary by person and hand, so measure the intended finger directly.
Do both hands use the same ring size?
Not necessarily. Measure the exact hand and finger where the ring will be worn.
See the full international ring size chart
Inch answer
Finger inches to ring size: around vs across
Multiply inches by 25.4, then match the correct measurement column.2¼″ around57.2 mm circumference≈ US 8
¾″ across a ring19.05 mm inner diameter≈ US 9
| Around finger | Circumference | Closest US size | EU |
|---|---|---|---|
| 2 in | 50.8 mm | 5.5 | 51 |
| 2.125 in | 54.0 mm | 7 | 54 |
| 2.25 in | 57.1 mm | 8 | 57 |
| 2.375 in | 60.3 mm | 9.5 | 61 |
| 2.5 in | 63.5 mm | 10.5 | 63 |
Do not enter a finger circumference as diameter: those are different measurements. If your number falls between rows, use the converter above and confirm with a second method.