Size Guide

MERVAUX rings are made one at a time and each one exists in a single size, currently US 6 through US 7.5. The chart below converts any US size into millimeters and into the UK, European and Japanese scales. If you would rather measure at home, there is a sizer you can print further down, accurate to the millimeter.

Start here

How sizes are written on our product pages

Every listing carries its measurement in the size field rather than in a separate chart, because each piece is finished in one size and is not made again in others.

Rings

US 7 (CN 14)

Two numbers, one finger. US 7 is the American scale; CN 14 is the same circumference written in the Chinese and Japanese scale, which our workshop uses. Stock runs US 6, 6.5, 7 and 7.5, and most pieces are US 7.

Necklaces and bracelets

Centimeters

Chain lengths are given in centimeters. A necklace marked 45 cm is 17.7 in; a bracelet marked 17 cm is 6.7 in. A length written as 38+2 cm has a 2 cm extender, so it wears anywhere from 15.0 to 15.7 in.

Earrings and stones

Millimeters

Stones are listed by carat weight, which is mass rather than width. The stud table below gives the face-up diameter in millimeters for each common weight, which is what actually reads on an ear.

Rings

Ring size chart

Ring size is the inside measurement of the band, so the number that travels between countries is the circumference in millimeters. Everything else on this table is that one measurement written in a different notation. Sizes we currently hold are marked.

US sizes 3 to 13 in half steps. Inside circumference and diameter are calculated from the American standard, where diameter in millimeters equals 11.63 plus 0.8128 for each size. Letter and numeric scales abroad step at different intervals, so they are rounded to the nearest size available in that system.
US & Canada Inside circumference (mm) Inside circumference (in) Inside diameter (mm) UK, Australia, Ireland France, EU (ISO) Japan, China, India
3 44.2 1.74 14.07 F½ 44.2 4
3.5 45.5 1.79 14.47 G½ 45.5 5
4 46.8 1.84 14.88 H½ 46.8 7
4.5 48.0 1.89 15.29 I½ 48.0 8
5 49.3 1.94 15.69 J½ 49.3 9
5.5 50.6 1.99 16.10 K½ 50.6 10
6 51.9 2.04 16.51 L½ 51.9 12
6.5 53.1 2.09 16.91 M½ 53.1 13
7 54.4 2.14 17.32 N½ 54.4 14
7.5 55.7 2.19 17.73 O½ 55.7 15
8 57.0 2.24 18.13 P½ 57.0 16
8.5 58.2 2.29 18.54 Q½ 58.2 18
9 59.5 2.34 18.95 R½ 59.5 19
9.5 60.8 2.39 19.35 S½ 60.8 20
10 62.1 2.44 19.76 T½ 62.1 21
10.5 63.3 2.49 20.16 U½ 63.3 22
11 64.6 2.54 20.57 V½ 64.6 24
11.5 65.9 2.59 20.98 W½ 65.9 25
12 67.2 2.64 21.38 X½ 67.2 26
12.5 68.5 2.70 21.79 Z 68.5 27
13 69.7 2.75 22.20 Z+1 69.7 29

Ring sizes are not standardized worldwide. The US scale is numeric, the UK scale is alphabetic, the European scale is the circumference itself, and the Japanese scale counts in its own steps. A conversion is therefore always a nearest match rather than an exact equivalence, which is why the millimeter column is the one to trust.

Method

Three ways to find your ring size

From a ring you already wear

Take a ring that fits the right finger, print the sizer below, and lay the ring over the circles until one disappears exactly under the inside edge of the band. Read the size printed above that circle. This is the most reliable method at home because it measures a finished object rather than a finger.

With a strip of paper

Cut a strip about 5 mm wide, wrap it around the base of the finger, and mark where the end overlaps. Flatten it, measure the marked length in millimeters against the printed ruler, and find that number in the circumference column above. Between two sizes, take the larger one.

At a jeweler

A jeweler sizes with a set of steel rings, which is more accurate than anything paper can do and takes about a minute. Worth doing if the piece is a gift, or if the knuckle is noticeably wider than the base of the finger, which changes the answer.

What moves the answer by half a size

Time of day. Fingers are at their smallest in the morning and swell through the day. Measure in the evening, at normal body temperature, and repeat it on two or three different days.

Temperature. Cold hands can measure up to half a size smaller than the same hands warm. Do not size a finger that has just come in from the cold.

Band width. A wide band sits against more of the finger and fits tighter than a narrow one at the same size. For a band over about 6 mm, allow a quarter to half a size more.

If the knuckle is much wider than the base of the finger, size for the knuckle so the ring can pass, then expect some movement once it is on. A jeweler can add sizing beads inside the shank to take up the difference.

Print at home

Printable ring sizer

Print this section at 100 per cent, or Actual size, with page scaling and fit to page switched off. Check the calibration bar with a ruler before using anything else on the sheet: if the bar is not 50 mm, nothing else on it is right either.

1  Check the scale

This bar must measure exactly 50 mm, or 1.97 in, edge to edge.

2  Measure a ring you already own

Lay the ring over the circles. The correct size is the circle whose edge sits just inside the band.

4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
10.5
11
11.5
12

3  Or measure the finger

Wrap a paper strip around the base of the finger, mark the overlap, then measure the marked length here in millimeters and read it against the circumference column of the chart.

Necklaces

Necklace length guide

Our chains are listed in centimeters. Where a length sits depends on the neck it is on, so the descriptions below are for an average adult neck of about 33 to 36 cm and shift by roughly one step either way outside that range. To measure, run a soft tape or paper strip around the neck where you want the chain to fall, then read the length.

Length (cm) Length (in) Name Where it falls At MERVAUX
35–37 14 Collar Tight around the base of the neck —
38–41 15–16 Choker At the base of the throat, above the collarbone 38+2 cm, 40 cm
42–46 17–18 Princess On or just below the collarbone 43 cm, 45 cm
50–56 20–22 Matinee Between the collarbone and the bust 55 cm
60–71 24–28 Opera At or below the sternum —
76 and over 30 and over Rope Below the bust, or doubled —

A pendant hangs below the chain line by the height of the drop, so a 45 cm chain with a 10 mm pendant reads about a centimeter lower than a plain 45 cm chain. Layering reads best with about 5 cm between chains, which is why our 40 cm and 45 cm lengths are built to sit together.

Bracelets

Bracelet and tennis bracelet sizing

Measure the wrist just below the wrist bone, where the bracelet will sit, using a paper strip and the printed ruler above. Then add for movement: about 1.0 to 1.5 cm for a close fit that stays put, and 2.0 to 2.5 cm for a looser one that slides. A line-set diamond bracelet is usually worn on the closer end, because a loose one turns over and wears the stones face down.

Wrist (cm) Wrist (in) Close fit Looser fit
14.0 5.5 15.0–15.5 cm 16.0–16.5 cm
15.0 5.9 16.0–16.5 cm 17.0–17.5 cm
16.0 6.3 17.0–17.5 cm 18.0–18.5 cm
17.0 6.7 18.0–18.5 cm 19.0–19.5 cm
18.0 7.1 19.0–19.5 cm 20.0–20.5 cm

We currently hold bracelets at 16, 16.5, 17 and 18 cm, which is 6.3 to 7.1 in. Rows marked in stock are the wrist measurements those lengths were made for.

Earrings

What a carat weight looks like on an ear

Carat is a measure of weight, not of width, so it does not tell you how large a stud will read. For a round brilliant cut to standard proportions, face-up diameter runs close to 6.5 mm times the cube root of the carat weight. Two points worth knowing before comparing listings: a stud pair sold as one carat total weight is two half-carat stones, each about 5.2 mm, not two stones of 6.5 mm; and shallow-cut stones of the same weight look wider but return less light.

Carat, per stone Face-up diameter (mm) Sold as a pair
0.25 ct 4.1 0.50 ct total weight
0.50 ct 5.2 1.00 ct total weight
0.75 ct 5.9 1.50 ct total weight
1.00 ct 6.5 2.00 ct total weight
1.50 ct 7.4 3.00 ct total weight
2.00 ct 8.2 4.00 ct total weight

Figures are for round brilliant cuts at standard depth. Elongated shapes such as oval, pear and marquise read wider than a round of the same weight in one direction and narrower in the other, which is covered on the Diamonds page.

If your size is not the one listed

Each piece is finished in a single size, so the size on the listing is the size that exists. When a piece you want is not in your size, tell us which piece and which size, and we will come back with what can be made, how long it takes and what it costs. The same applies to a chain length we do not stock.

Ask about a size Find your stone Rings Necklaces Bracelets Earrings

Common questions

What ring sizes does MERVAUX carry?
US 6, 6.5, 7 and 7.5, with most pieces made in US 7. Each ring is finished in a single size rather than produced across a size run, so the size shown on a listing is the size that exists. If a piece you want is not in your size, ask us on the contact page and we will come back with what can be made, how long it takes and what it costs.
What does US 7 (CN 14) mean on a ring listing?
Two numbers for one finger. US 7 is the American scale and CN 14 is the same circumference written in the Chinese and Japanese numbering our workshop uses. Both describe an inside circumference of 54.4 mm and an inside diameter of 17.3 mm. The full conversion is on the size guide.
How do I measure my ring size at home?
Two methods work without a jeweler. Lay a ring that already fits over the printed circles on our printable sizer and read the size of the circle that sits just inside the band. Or wrap a 5 mm paper strip around the base of the finger, mark the overlap, measure that length in millimeters, and find it in the circumference column of the chart. Measure in the evening at normal body temperature, and repeat on two or three days.
What unit are ring sizes measured in?
Inside circumference, in millimeters, on every system in the world. A US 6 is 51.9 mm, a US 7 is 54.4 mm and a US 8 is 57.0 mm. The national scales are only different notations for that one number: the European size is the circumference itself, the German scale is the inside diameter, and the UK scale uses letters that step every 1/64 inch of diameter.
Are ring sizes the same in every country?
No. The US scale is numeric, the UK and Australian scale is alphabetic, the French and European scale is the circumference in millimeters, and Japan, China and India use a third numbering. The steps do not line up, so a conversion between them is a nearest match rather than an exact equivalence. When you need to be certain, carry the millimeter measurement rather than the local size number.
What should I do if I am between two ring sizes?
Take the larger size. A ring that will not pass the knuckle cannot be worn at all, while one that is slightly loose still can. Go up rather than down when the band is wide, since a band over about 6 mm fits tighter than a narrow one at the same size, and when the knuckle is noticeably wider than the base of the finger.
What necklace length should I choose?
For an average adult neck, 38 to 41 cm sits at the base of the throat, 42 to 46 cm falls on or just below the collarbone, and 50 to 56 cm sits between the collarbone and the bust. MERVAUX chains are listed in centimeters: 45 cm is 17.7 in. To layer two chains, leave about 5 cm between them. The full table is on the size guide.
How large does a one carat diamond stud look?
About 6.5 mm across the face for a round brilliant at standard proportions, since face-up diameter runs near 6.5 mm times the cube root of the carat weight. Note that studs sold as one carat total weight are two half carat stones of about 5.2 mm each, not two stones of 6.5 mm. Earrings are listed by total weight.