Skip to content
ringsizerchart

US ring size 3

A US size 3 ring is 14.07 mm (0.554") across the inside and 44.2 mm (1.74") round. It converts to UK F½, EU 44, Japan 4 and Swiss 4. The 1:1 circle below is already set to size 3: 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 314.07 mm · 0.554" inside · 44.2 mm round
Inside diameter14.07 mm
Band wall1.8 mm
Jump to US

Full chart 19 rows

Sort any column, download it as CSV or print it. Click a row to show it at 1:1.

Size 3 and the quarter sizes around it

9 rows
Download CSV
US ring size 3 and quarter sizes within one size either side: inside diameter, difference in mm, circumference, UK and EU sizes
Actions
13.26−0.81 mm41.6D½42
13.46−0.61 mm42.3E42
13.66−0.41 mm42.9E½43
13.87−0.20 mm43.6F44
14.07—44.2F½44
14.27+0.20 mm44.8G45
14.47+0.41 mm45.5G½45
14.68+0.61 mm46.1H46
14.88+0.81 mm46.8H½47

Ordering a size 3 in different band widths

4 rows
Download CSV
What size to order for a US size 3 finger in narrow, 4–6 mm, 7 mm and wider, and comfort-fit bands
Actions
314.07Bands under 4 mm usually fit true to size.
3¼–3½14.27–14.47A 4–6 mm band covers more skin and feels snugger: jewellers suggest a quarter to a half size up.
3½–414.47–14.88Wide and cigar bands grip the whole finger segment: half a size to a full size up.
2½–2¾13.66–13.87A domed comfort-fit inside slips over the knuckle more easily: often a quarter to a half size down.

Blank length for a size 3 band

6 rows
Download CSV
Length of wire or sheet to cut for a US size 3 ring band (14.07 mm inside) in stock 1.0 to 2.5 mm thick, by π × (inside diameter + thickness)
Actions
47.31.864"16.07
48.01.888"16.47
48.91.926"17.07
49.91.963"17.67
50.51.987"18.07
52.12.049"19.07

05 / Field guide

Size 3,
14.07 mm inside.

Everything about a US 3: 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 3½.

Who wears a size 3

A US 3 is a petite size: little fingers, midi rings worn above the knuckle, and many teenagers. Jewellers’ order data puts the most common women’s size at 7 and men’s at 10, so a 3 is 4 sizes below the usual women’s size and 7 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 2½ (13.66 mm) and 0.41 mm narrower than a 3½ (14.47 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 3 by most of a size.

Size 3 in the UK, Europe and Japan

A 3 is 44.2 mm round. UK letters on the BS 6820 scale cover 0.625 mm each with half sizes, and F½ runs from 44.06 to 44.69 mm, so a 3 sits near the bottom of F½. If you are on the small side of a 3, a UK F may suit better.

ISO 8653 rounds to the nearest millimetre, so EU 44 covers 43.5 to 44.5 mm and a 3 lands 0.70 mm into that band. Swiss and Italian sizes subtract 40, giving 4. Japan 4 is 14.0 mm inside, 0.07 mm smaller than a US 3, so Japanese 4 is the nearest match.

Quarter sizes either side

A 2¾ is 13.87 mm and a 3¼ is 14.27 mm, each about 0.2 mm from a 3: roughly the thickness of two sheets of paper on the diameter. If your ring falls between 2¾ and 3¼ on the 1:1 circle, order a 3 for a band under 4 mm.

For a 4–6 mm band, jewellers suggest 3¼ to 3½; for 7 mm and wider, 3½ to 4; for a comfort-fit inside, 2½ to 2¾. No current smart ring comes in this size.

Making a size 3 band

The blank length is the circumference of the middle of the band wall: π × (14.07 + thickness). Cut 48.9 mm of 1.5 mm stock or 50.5 mm of 2.0 mm stock, and the finished band has an outside diameter of 17.07 or 18.07 mm. Leave a little extra for filing the joint, and true the band on a mandrel at 3 after soldering.

Blank = π × (14.07 mm + t) · 1.5 mm → 48.9 mm · 2.0 mm → 50.5 mm

Questions

Answered plainly.

01What is a size 3 ring in mm?+

A US size 3 ring is 14.07 mm (0.554") across the inside, with an inside circumference of 44.2 mm (1.74").

02What is a US size 3 in UK and EU sizes?+

US 3 is UK F½ and EU (ISO 8653) 44. It is also Japan 4 and Swiss 4.

03How much bigger is a size 3½ than a size 3?+

A size 3½ is 0.41 mm wider inside (14.47 against 14.07 mm) and 1.28 mm longer round.

04How long a blank do I cut for a size 3 ring?+

48.9 mm for 1.5 mm thick stock and 50.5 mm for 2.0 mm, from π × (14.07 mm + thickness).

05Should I order a size 3 for a wide band?+

For a band 7 mm or wider, jewellers suggest 3½ to 4; for 4–6 mm, 3¼ to 3½. Under 4 mm, a 3 fits true to size.

Ring sizesUS · inside Ø mm

Carat sizes

Necklace lengths