getting the size right before you order saves time and ensures a piece you can wear immediately. three methods to find your ring size at home — including our own online ring sizer — plus a full US, EU, and UK conversion chart.
ring sizing is one of the most common reasons a piece needs to be returned or resized after purchase. a half size off in either direction can make the difference between a ring that stays in place and one that spins, catches, or won't go on at all.
we built a ring sizer tool directly into our website to make this as simple as possible — no apps, no printing, no plastic gauges. if you have a ring that already fits and any standard card in your wallet, you can find your exact size in under two minutes at juwels.co/pages/ring-sizer.
below is how the tool works, plus two manual backup methods if you don't have an existing ring to measure from.
method 1 — the juwels & co ring sizer
the most accurate at-home method, and the one we recommend before ordering. our ring sizer lives directly on our website — no app, no download, no printing. it works on any phone, tablet, or laptop and gives you your size in US, EU, and UK formats in under two minutes.
find your ring size now
works on any device. takes under two minutes. no printing or tools required.
open the ring sizer →How the tool works
calibrate your screen
- place your credit card flat on the screen
- use the slider to resize the on-screen box until it matches your card exactly, edge to edge
- once calibrated, the tool knows your screen's true dimensions — you only need to do this once per device
measure your ring
- place the ring flat on your screen, over the circle guide
- use the slider to resize the circle until its inner edge matches your ring's inner edge exactly
- select your preferred size system (US, EU, or UK) — your size appears instantly
method 2 — paper or string
the classic method for measuring a finger you don't already have a ring for. accurate when done carefully, but requires attention to technique — a strip that's too loose or too tight will give you the wrong size.
a thin strip of paper (or string) + a pen + a ruler
- cut a thin strip of paper about 10cm long and 5mm wide (or use a piece of string)
- wrap it snugly around the base of the finger you want to size — snug, not tight
- mark where the paper overlaps with a pen
- lay the paper flat against a ruler and measure the length in millimeters — this is your finger circumference
- use the conversion chart below to find your ring size
method 3 — measure an existing ring
if you already own a ring that fits the finger you're sizing, measuring its inner diameter gives you a precise reference. this works particularly well for sizing the right hand or a specific finger you don't have an easy way to wrap.
a ring that fits + a ruler (or the ring sizer tool)
- place the ring flat on a ruler
- measure the inner opening — the distance from one inner edge to the opposite inner edge — in millimeters
- this is your inner diameter
- use the conversion chart below to match the diameter to your ring size
this is also what our online ring sizer does digitally — if you have the ring but want to skip the ruler, the tool will match it for you with greater precision.
sizing tips worth knowing
- Measure at the right time of day fingers are slightly larger in the evening than in the morning, and expand in warm weather and contract in cold. measure at the end of the day, at room temperature, for the most reliable fit.
- Account for the knuckle if your knuckle is noticeably wider than the base of your finger, the ring needs to pass over the knuckle to reach its resting position. in this case, size to the knuckle rather than the base — the ring will sit slightly loosely, but it will actually go on.
- Narrow bands fit tighter a 1.5mm band feels tighter than a 3mm band at the same numerical size because there's less surface area distributing the pressure. if you're between sizes for a thin band, size up.
- Right hand vs. left hand your dominant hand is typically slightly larger than your non-dominant hand. if you're sizing for your right hand and only have a ring from your left, measure the actual finger rather than assuming the same size.
- When in doubt, go slightly larger a ring that's slightly large can be sized down. a ring that won't go on can't be worn. if you're genuinely between two sizes, order the larger one — or reach out and we'll advise based on the specific piece.
- Free resizing at juwels & co we offer free resizing on all our pieces. if your ring arrives and the fit isn't right, reach out at hello@juwels.co and we'll sort it — no questions, no cost.
us, eu & uk ring size conversion chart
all juwels & co rings are sized in US ring sizes, available in whole, half, and quarter sizes. use the chart below to convert from EU (inner diameter in mm) or UK (letter sizing) to your US size.
| US Size | Inner Diameter (mm) | Circumference (mm) | EU Size | UK Size |
|---|---|---|---|---|
| 4 | 14.9 | 46.8 | 47 | H |
| 4.5 | 15.3 | 48.0 | 48 | I |
| 5 | 15.7 | 49.3 | 49 | J½ |
| 5.5 | 16.1 | 50.6 | 51 | K½ |
| 6 | 16.5 | 51.8 | 52 | L½ |
| 6.5 | 16.9 | 53.1 | 53 | M½ |
| 7 | 17.3 | 54.4 | 54 | N½ |
| 7.5 | 17.7 | 55.7 | 56 | O½ |
| 8 | 18.1 | 56.9 | 57 | P½ |
| 8.5 | 18.5 | 58.2 | 58 | Q½ |
| 9 | 18.9 | 59.5 | 60 | R½ |
| 9.5 | 19.4 | 60.8 | 61 | S½ |
| 10 | 19.8 | 62.1 | 62 | T½ |
| 10.5 | 20.2 | 63.4 | 63 | U½ |
| 11 | 20.6 | 64.6 | 65 | V½ |
| 11.5 | 21.0 | 65.9 | 66 | W½ |
| 12 | 21.4 | 67.2 | 67 | X½ |
not sure which finger to measure, or sizing for a pinky or index ring? reach out at hello@juwels.co — we can guide you through it before you order.
frequently asked questions
how do I measure my ring size at home?
what is the average ring size for women?
what is the average ring size for men?
what if I'm between ring sizes?
can fingers change size over time?
how do I convert EU ring size to US?
how do I convert UK ring size to US?
does juwels & co offer free resizing?
ready to find your size?
use our online ring sizer for an accurate result in under two minutes — then explore our collection, made to order in your exact size.
