Finding the perfect piece in 18-carat gold is an exceptional experience, but ordering it online can sometimes give rise to a legitimate hesitation. To buy at a distance with confidence, you need to know precisely how to measure a ring size without any risk of error. Written with our expert jewellers at Salia Gold Paris, this practical guide is designed to remove every doubt.
Whether you want to measure your own finger or prepare an unforgettable surprise, here are our precise methods, our professional tips and our detailed conversion table, so that you can choose with complete peace of mind.
Why is it so important to measure your finger accurately?
The harmony and the longevity of your jewellery rest on absolute precision. A badly fitted ring is liable to slip off, while one that is too tight will affect your comfort, and even your circulation. Although subtle differences may exist from one workshop to another, the metric measurement remains the universal reference standard. In France, sizing is beautifully simple: it corresponds to the circumference of your finger. A size 52, therefore, matches a circumference of exactly 52 millimetres.
Method 1: using a printable ring sizer (the most accurate)
After the professional mandrel used in the workshop, the most reliable tool at home remains the printed or on-screen ring sizer. To measure a ring size with this tool, you simply compare a ring you already wear against our calibrated circles.
How to use our printed or on-screen ring sizer
For this method to work, accuracy of scale is essential. The most common mistake is printing the document with automatic resizing switched on.
Checklist before printing:
- Download our ring sizer in PDF format.
- In the print settings, be sure to select "Scale 100%" or "Actual size" (no scaling).
- The bank card trick: to check the calibration of your print (or of your screen, if you are using the on-screen sizer), place a standard credit card on the visual guide provided. If the card matches the outline exactly, your scale is correct.
Instructions: take a ring that fits the intended finger perfectly. Place it over the different circles on the sizer. The correct circle should be visible inside the ring, just touching the inner edge of the metal, without the line being hidden by the band.
Method 2: measuring the diameter of an existing ring
If you do not have a printer, a simple ruler will do, provided you are extremely precise.
Take a ring that corresponds to the intended finger and place it on a flat surface. Using your ruler, measure the inner diameter of the band. Take care not to include the thickness of the metal in your measurement: only the empty space from one inner edge to the other.
Once you have the diameter in millimetres, you can apply the following formula to find the circumference, and therefore your French size:
Example: if your inner diameter is 16.5 mm, then 16.5 × 3.14 = 51.81. Your ideal size is 52.
Method 3: measuring the circumference of your finger
If you have no reference ring to hand, you can measure your finger directly with a tailor's tape measure, a narrow ribbon, or even a strip of paper.
- Wrap the tape or the strip around the base of the intended finger.
- Expert tip: do not pull it tight. The tape must be able to pass over your knuckle, which is often the widest part of the finger.
- Mark with a pen the point where the tape overlaps.
- Unwrap the tape and measure the distance between the starting point and your mark with a millimetre ruler. That distance in millimetres gives you your French size directly.
Ring size conversion table (FR, US, UK)
To make online shopping and international conversions easier, here is the jeweller's reference table drawn from our professional charts. Use your inner-diameter or circumference measurement to find your size.
| Inner diameter (⌀ mm) | FR size (circumference) | US size | UK size |
|---|---|---|---|
| 14 | 44 | 3 | F |
| 14.3 | 45 | 3.5 | G |
| 15 | 47 | 4 | H 1/2 |
| 15.3 | 48 | 4.5 | I 1/2 |
| 15.6 | 49 | 5 | J 1/2 |
| 15.9 | 50 | 5.5 | K 1/2 |
| 16.2 | 51 | 5.75 | L |
| 16.5 | 52 | 6 | M |
| 16.8 | 53 | 6.5 | N |
| 17.2 | 54 | 7 | O |
| 17.5 | 55 | 7.5 | P |
| 18.1 | 57 | 8 | Q |
| 18.4 | 58 | 8.5 | R |
| 18.8 | 59 | 9 | S 1/2 |
| 19.4 | 61 | 9.75 | T |
| 20 | 63 | 10.5 | U 1/2 |
| 20.6 | 65 | 11.5 | W 1/2 |
| 21.3 | 67 | 12 | Y |
| 22 | 69 | 13 | Z+1 |
(Note: if your measurement falls between two intermediate millimetre values not listed here, refer to the rule about going up a size, explained below.)
Five expert tips so you never get it wrong
To achieve the precision of a fitting in the workshop, our jewellers recommend taking these anatomical factors into account:
- Temperature (swollen fingers): your fingers react to changes in temperature. They contract in the cold and tend to swell with heat or physical effort. Ideally, measure your finger at the end of the day, when your hands are at a normal temperature and your fingers are at their fullest.
- The knuckle rule: a well-fitted ring should offer slight resistance as it passes the knuckle, so that it does not slide off on its own, but it should sit comfortably at the base of the finger without compressing it.
- Your dominant hand: anatomy is not perfectly symmetrical. For most people, the fingers of the dominant hand (the right hand, for right-handers) are slightly stronger, and sometimes need half a size more. Always measure the specific finger of the exact hand on which the ring will be worn.
- The width of the band: very fine rings slip on easily. A wide band (over 5 mm), on the other hand, covers a larger area of skin and grips the finger more firmly. For wide models, it is often advisable to go one size up from your standard measurement.
- Between two sizes? If your measurement falls exactly between two sizes on the sizer, always choose the larger. Fingers can swell over the course of a day, and a piece that is very slightly loose is far more pleasant to wear than a band that presses.
FAQ: quick answers to your questions
What is a "comfort fit" ring, and how does it affect the size?
"Comfort fit" rings have a slightly domed, softened interior. This ergonomic shape allows them to pass over the knuckle more easily. With this profile, some clients prefer to choose half a size below their standard size for a perfect hold, although your usual size generally remains very comfortable.
How do I measure my finger if I have arthritis or large joints?
If your knuckle is significantly wider than the base of your finger, measure both areas separately, then choose an intermediate size. The ring must pass the joint — even with a very slight push — so that it is not excessively loose once it reaches the base of the finger. A jeweller can also add sizing beads inside the band to stop it turning.
How can I measure a ring size discreetly, for a gift?
The most reliable technique for a surprise, such as an engagement ring, is to borrow for a moment a ring the person wears regularly on the intended finger (usually the left ring finger). Place the ring on a sheet of paper and draw round the inner edge precisely with a very fine pencil. You can then measure the diameter of the circle you have drawn.
Can every piece be resized afterwards?
Solitaire rings lend themselves readily to resizing. Full-eternity bands set with stones all the way round, however, cannot be resized without altering their structure — which is why it matters so much to measure a ring size correctly the first time.
Should I take my measurement if I am pregnant?
Pregnancy frequently brings water retention, which changes the volume of the fingers. If you are expecting a child, your current measurements will not represent your usual size. It is better to wait a few months after the birth before investing in a lasting piece of fine jewellery.
How do I choose my size for stacking several rings?
When you wear several fine rings on the same finger, they act collectively as one very wide band. It is often wise to choose the uppermost ring — the one closest to the joint — half a size larger, to avoid any compression of the finger.
Salia Gold: a piece to keep for life
At Salia Gold, we create exceptional pieces in 18-carat gold, where design, emotion and enduring value meet. Our creations bring together traditional French handcraft and absolute precision.
Because real gold keeps its splendour and its value, we offer a lifetime service for the maintenance, resizing and cleaning of your pieces, for our private clients. Looking for the ideal gift, or would you like to try our creations? Our expert jewellers are entirely at your disposal to measure your finger with professional precision, using our reference mandrels.
Buy online or discover Salia Gold in Paris
Address: 22 Rue Vignon, 75009 Paris, France
Telephone: +33 1 71 28 40 62
Discover our 18-carat gold collections: rings, necklaces, bracelets and earrings, entirely made in France. Ready to give in their Salia Gold case — explore the online boutique.