Ring Size Chart: US Sizes in MM (Printable)
Updated: 2 days ago
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Measure the inside diameter of a ring that already fits, in millimetres, and find it below. That is the most accurate method that doesn't involve a jeweller.
US ring sizes in millimetres
Format: US size — inside diameter — circumference
3 — 14.1 mm — 44.2 mm
3.5 — 14.5 mm — 45.5 mm
4 — 14.9 mm — 46.8 mm
4.5 — 15.3 mm — 48.0 mm
5 — 15.7 mm — 49.3 mm
5.5 — 16.1 mm — 50.6 mm
6 — 16.5 mm — 51.9 mm
6.5 — 16.9 mm — 53.1 mm
7 — 17.3 mm — 54.4 mm
7.5 — 17.7 mm — 55.7 mm
8 — 18.2 mm — 57.0 mm
8.5 — 18.5 mm — 58.3 mm
9 — 19.0 mm — 59.5 mm
9.5 — 19.4 mm — 60.8 mm
10 — 19.8 mm — 62.1 mm
10.5 — 20.2 mm — 63.4 mm
11 — 20.6 mm — 64.6 mm
11.5 — 21.0 mm — 65.9 mm
12 — 21.4 mm — 67.2 mm
12.5 — 21.8 mm — 68.5 mm
13 — 22.2 mm — 69.7 mm
We make rings in US sizes 2 to 13 in quarter-size increments, so if you land between two sizes we can usually make the quarter size between them.
UK and EU equivalents
US 4 = UK H = EU 47
US 5 = UK J½ = EU 49
US 6 = UK L½ = EU 52
US 7 = UK N½ = EU 54
US 8 = UK P½ = EU 57
US 9 = UK R½ = EU 59
US 10 = UK T½ = EU 62
US 11 = UK V½ = EU 65
US 12 = UK Y = EU 67
Two ways to measure at home
From a ring that fits. Lay it on a ruler and measure straight across the inside, at the widest point. Half a millimetre is most of a size, so measure twice.
From the finger. Wrap a strip of paper around the base of the finger, mark where it overlaps, and measure the length. That is the circumference. Avoid string and thread, which stretch and read a size small.
Four things that change the answer
Temperature. Fingers shrink in cold and swell in heat. Measure at the end of a warm day.
Band width. Above 6 mm, go up a quarter to a half size.
Knuckles. The ring must pass the knuckle. If your knuckle is much larger, size for it and add sizing beads.
Which hand. The dominant hand usually runs about half a size larger.
Printing this chart
Use your browser's print function. Do not print a paper ring sizer scaled to fit the page, which is the most common source of error — printable sizers only work at exactly 100% scale, and you should verify with a ruler before trusting one.
Frequently asked questions
What is the average ring size?
About US 6 to 6.5 for women and 9 to 10 for men, though variation is wide.
What if I'm between sizes?
Go up. A loose ring can be padded or resized down; a tight one cannot be worn while you wait.
Can rings be resized later?
Most solid gold rings can move a size or two. Full eternity bands usually cannot, and neither can plated or tungsten rings.
How do I measure a ring size secretly?
Borrow a ring she wears on the right finger and measure the inside diameter, or press it into soap and measure the impression. Our surprise sizing guide covers the rest.
Browse engagement rings and wedding bands in US sizes 2 to 13.
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