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US ring size 7

A US size 7 ring is 17.32 mm (0.682") across the inside and 54.4 mm (2.14") round. It converts to UK N½, EU 54, Japan 14 and Swiss 14.5. The 1:1 circle below is already set to size 7: lay a ring on it to check yours.

Try

Lay a ring that fits flat on the circle and size the red line until it just touches the inside edge of the band all the way round: on a phone, slide sideways anywhere on the stage or hold the buttons below; on a computer, drag the edge, scroll or press ← →. The gold ring is the band’s wall: don’t match its outside.

US 717.32 mm · 0.682" inside · 54.4 mm round
Inside diameter17.32 mm
Band wall1.8 mm
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Full chart 19 rows

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Size 7 and the quarter sizes around it

9 rows
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US ring size 7 and quarter sizes within one size either side: inside diameter, difference in mm, circumference, UK and EU sizes
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16.51−0.81 mm51.9L½52
16.71−0.61 mm52.5M52
16.91−0.41 mm53.1M½53
17.12−0.20 mm53.8N54
17.32—54.4N½54
17.52+0.20 mm55.0O55
17.73+0.41 mm55.7O½56
17.93+0.61 mm56.3P56
18.13+0.81 mm57.0P½57

Ordering a size 7 in different band widths

4 rows
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What size to order for a US size 7 finger in narrow, 4–6 mm, 7 mm and wider, and comfort-fit bands
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717.32Bands under 4 mm usually fit true to size.
7¼–7½17.52–17.73A 4–6 mm band covers more skin and feels snugger: jewellers suggest a quarter to a half size up.
7½–817.73–18.13Wide and cigar bands grip the whole finger segment: half a size to a full size up.
6½–6¾16.91–17.12A domed comfort-fit inside slips over the knuckle more easily: often a quarter to a half size down.

Blank length for a size 7 band

6 rows
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Length of wire or sheet to cut for a US size 7 ring band (17.32 mm inside) in stock 1.0 to 2.5 mm thick, by π × (inside diameter + thickness)
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57.62.266"19.32
58.22.291"19.72
59.12.328"20.32
60.12.365"20.92
60.72.390"21.32
62.32.451"22.32

05 / Field guide

Size 7,
17.32 mm inside.

Everything about a US 7: what it measures, who usually wears it, how it converts in each country, the quarter sizes around it and what to order for wide bands. Neighbouring sheets: size 6½ and size 7½.

Who wears a size 7

A US 7 is the most common women’s ring size in jewellers’ order data. Jewellers’ order data puts the most common women’s size at 7 and men’s at 10, so a 7 is exactly the usual women’s size and 3 sizes below the usual men’s size. The same finger is often a quarter to half size larger on the dominant hand.

It is 0.41 mm wider inside than a 6½ (16.91 mm) and 0.41 mm narrower than a 7½ (17.73 mm). On the circumference that is 1.28 mm per half size, which is why a strip of string, stretching a couple of millimetres as you pull it snug, can misread a 7 by most of a size.

Size 7 in the UK, Europe and Japan

A 7 is 54.4 mm round. UK letters on the BS 6820 scale cover 0.625 mm each with half sizes, and N½ runs from 54.06 to 54.69 mm, so a 7 sits in the middle of N½. It converts cleanly, so a UK N½ ring should feel the same.

ISO 8653 rounds to the nearest millimetre, so EU 54 covers 53.5 to 54.5 mm and a 7 lands 0.91 mm into that band. Swiss and Italian sizes subtract 40, giving 14.5. Japan 14 is 17.3 mm inside, 0.02 mm smaller than a US 7, so Japanese 14 is the nearest match.

Quarter sizes either side

A 6¾ is 17.12 mm and a 7¼ is 17.52 mm, each about 0.2 mm from a 7: roughly the thickness of two sheets of paper on the diameter. If your ring falls between 6¾ and 7¼ on the 1:1 circle, order a 7 for a band under 4 mm.

For a 4–6 mm band, jewellers suggest 7¼ to 7½; for 7 mm and wider, 7½ to 8; for a comfort-fit inside, 6½ to 6¾. Smart-ring kits that include a size 7 sample: Oura Ring 4, Galaxy Ring, Ring AIR.

Making a size 7 band

The blank length is the circumference of the middle of the band wall: π × (17.32 + thickness). Cut 59.1 mm of 1.5 mm stock or 60.7 mm of 2.0 mm stock, and the finished band has an outside diameter of 20.32 or 21.32 mm. Leave a little extra for filing the joint, and true the band on a mandrel at 7 after soldering.

Blank = π × (17.32 mm + t) · 1.5 mm → 59.1 mm · 2.0 mm → 60.7 mm

Questions

Answered plainly.

01What is a size 7 ring in mm?+

A US size 7 ring is 17.32 mm (0.682") across the inside, with an inside circumference of 54.4 mm (2.14").

02What is a US size 7 in UK and EU sizes?+

US 7 is UK N½ and EU (ISO 8653) 54. It is also Japan 14 and Swiss 14.5.

03How much bigger is a size 7½ than a size 7?+

A size 7½ is 0.41 mm wider inside (17.73 against 17.32 mm) and 1.28 mm longer round.

04How long a blank do I cut for a size 7 ring?+

59.1 mm for 1.5 mm thick stock and 60.7 mm for 2.0 mm, from π × (17.32 mm + thickness).

05Should I order a size 7 for a wide band?+

For a band 7 mm or wider, jewellers suggest 7½ to 8; for 4–6 mm, 7¼ to 7½. Under 4 mm, a 7 fits true to size.

Ring sizesUS · inside Ø mm

Carat sizes

Necklace lengths