Rings are the easiest piece of jewelry to order in the wrong size, and the most annoying one to get wrong. A necklace that's an inch off still looks good. A ring that's half a size off either won't go on, or won't stay on.
The good news: you don't need a ring sizer, an app, or a trip to a jeweller. You need a strip of paper and a ruler, and about two minutes.
The two-minute method
- Cut a strip of paper about 4 inches long and less than half an inch wide. (A strip of printer paper is perfect. String works too, but it stretches — paper is more accurate.)
- Wrap it around the base of the finger you'll wear the ring on. Snug, but not tight enough to pinch.
- Mark where the end overlaps with a pen.
- Unwrap it and measure from the end to your mark, in millimetres. That number is your finger's circumference.
- Find it in the chart below.
Measure the same finger twice, a few minutes apart. If you get two different numbers, take the larger one.
The chart
These are standard US ring sizes. Mondsee rings run from size 4 to 10.5, in half sizes.
| US size | Circumference (mm) | Inside diameter (mm) |
|---|---|---|
| 4 | 46.8 | 14.9 |
| 4.5 | 48.0 | 15.3 |
| 5 | 49.3 | 15.7 |
| 5.5 | 50.6 | 16.1 |
| 6 | 51.9 | 16.5 |
| 6.5 | 53.1 | 16.9 |
| 7 | 54.4 | 17.3 |
| 7.5 | 55.7 | 17.7 |
| 8 | 57.0 | 18.1 |
| 8.5 | 58.3 | 18.5 |
| 9 | 59.5 | 18.9 |
| 9.5 | 60.8 | 19.4 |
| 10 | 62.1 | 19.8 |
| 10.5 | 63.4 | 20.2 |
Sizes 6 through 9 are the most commonly ordered. If you're shopping for someone else and have nothing to go on, 7 is the single safest guess for a woman's ring finger — but read the gift section below before you rely on that.
If you already own a ring that fits
Easier still. Take a ring that fits the right finger, place it on a ruler, and measure straight across the inside of the band, edge to edge, in millimetres. That's the inside diameter — match it to the third column above.
Two cautions. Measure across the inside, not the outside, or you'll add the thickness of the band twice and land a full size too big. And make sure the ring you're copying belongs on the same finger of the same hand — most people's dominant hand is up to half a size larger.
Four things that throw the measurement off
- Cold hands. Fingers shrink noticeably in the cold. Measure in a warm room, with warm hands.
- Measuring first thing in the morning. Fingers are at their smallest overnight and swell through the day. Late afternoon or evening gives you the size you'll actually live in.
- Pulling the paper tight. It should sit the way a ring sits — resting, not gripping. If it leaves a mark on your skin, it's too tight.
- Forgetting the knuckle. The ring has to travel over your knuckle to get on. See the next section.
When your knuckle is bigger than your finger
This is common, and it's the one case where the chart alone will fail you.
Measure twice: once at the base of the finger, and once around the widest part of the knuckle. If the knuckle is more than about half a size larger, size to somewhere between the two numbers — closer to the knuckle measurement than the base one. A ring that spins slightly is a minor annoyance. A ring that won't go past your knuckle is unwearable.
Wider bands also need a little more room than thin ones. If you're between sizes on a band 6mm or wider, size up.
Between two sizes? Size up
Almost always. Fingers swell in heat, on flights, after salty food, and through the day. A ring that's a hair loose in the morning is comfortable by evening. A ring that's a hair tight in the morning is coming off with soap by lunch.
Adjustable rings — the safe choice when you're not sure
Some Mondsee rings are made with an adjustable band, which removes the guesswork entirely. Those come in three sizes:
- Small — fits roughly US 5 to 6.5
- Medium — fits roughly US 7 to 8.5
- Large — fits roughly US 9 to 10.5
If you're buying a gift, or you want one ring you can move between fingers, start there.
Sizing for a stack
Stacked rings behave differently from a single band. Three thin rings on one finger take up more room than the sum of their parts — they push each other apart slightly and sit higher on the finger.
If you're building a stack of three or more on the same finger, size the outer rings a half size up from your measured size and keep the middle one true. If you're spreading a stack across several fingers, measure each finger separately. Index and middle fingers are usually a size or more larger than the ring finger. Once everything fits, keeping the stack arranged the way you put it on is a separate problem — our guide to stacking rings so they actually stay stacked covers the friction and arrangement side of it.
Buying a ring as a surprise
Three approaches that actually work, in order of reliability:
- Borrow a ring she already wears on the correct finger and measure its inside diameter with the method above. Put it back before it's missed.
- Ask a friend or her mother. Slightly less romantic, considerably more accurate.
- Buy adjustable. No measuring, no guessing, no conversation that gives it away.
What doesn't work: guessing from the look of her hands, or comparing to your own finger. The error rate on both is high enough that you may as well flip a coin.
The short version
- Wrap paper around the base of the finger, mark the overlap, measure in millimetres.
- Match the number to the chart. Warm hands, late in the day.
- Check the ring will clear your knuckle.
- Between sizes, or wearing a wide band, size up.
- Not sure at all? Buy adjustable.
Still stuck? Email us at mondseecompany@gmail.com with your measurement and the ring you're looking at, and we'll size you personally — usually the same day.
Shop 18k gold-filled rings →
Full size guide: necklaces, bracelets, anklets →
— The Mondsee Atelier