A. Chuan Journal — Fit & Sizing
You can find your ring size at home in two reliable ways: measure the inner diameter of a ring that already fits, or wrap a strip of paper around your finger and measure the length. Both take under five minutes and need nothing more than a ruler.
This guide walks through each method, gives you a US size chart in millimetres, and explains why adjustable rings solve the problem entirely when you're buying for someone else.
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Reference
The size chart
Ring sizes in the US system correspond to the measurements below. Diameter is the straight line across the inside of the ring; circumference is the distance around your finger.
| US size | Inner diameter | Finger circumference |
|---|---|---|
| 5 | 15.7 mm | 49.3 mm |
| 6 | 16.5 mm | 51.9 mm |
| 7 | 17.3 mm | 54.4 mm |
| 8 | 18.1 mm | 57.0 mm |
| 9 | 18.9 mm | 59.5 mm |
If your measurement lands between two sizes, choose the larger one — a ring that slips slightly is wearable; a ring that pinches is not.
Method one
Measure a ring that already fits
This is the most accurate home method, because the ring has already done the fitting for you. Take a ring you wear comfortably on the intended finger and measure the widest inside distance with a ruler — ideally in millimetres.
- Measure inside edge to inside edge — the band itself doesn't count.
- Match the diameter to the chart above.
- Check the finger — the same size on a different finger won't transfer.
Method two
The paper-strip method
No ring to hand? Cut a strip of paper about five millimetres wide, wrap it snugly around the base of the finger, and mark where it overlaps. The length from end to mark is your circumference — match it to the chart.
Two details improve the result: measure at the end of the day, when fingers are at their fullest, and check that the strip passes back over the knuckle without forcing. If the knuckle is noticeably wider, size to the knuckle rather than the base.
Shop the pieceThe simpler answer
Why adjustable rings help
An adjustable ring has an open band that flexes gently to fit a range of sizes, so the measuring question largely disappears. Much of our ring collection is designed this way — the open band is part of the silhouette, not a compromise.
Adjust one slowly and only by small degrees: ease the band to the size you need and let it keep that shape, rather than bending it back and forth.
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Adjustable picks
Three that fit almost everyone
Each of these is built on an open, adjustable band — a sensible starting point when the size is a guess.
Deep colour
Lapis lazuli and red agate in a vintage-inspired setting.
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The statement
An oval agate and lapis lazuli piece that carries the whole hand.
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Quiet sparkle
Fluid lines with pavé cubic zirconia, subtle at any angle.
Shop the pieceGifting
Sizing a ring for someone else
Buying a ring as a gift is where sizing usually falls apart — you can hardly ask without giving the surprise away. Three quiet approaches work:
- Borrow a ring they already wear on the intended finger, and measure it with the chart above.
- Ask someone close — a sister or friend often knows, or can find out casually.
- Choose adjustable — an open band removes the guesswork entirely, which is why adjustable pieces gift so well.
If a ring is only part of the plan, our gifts under $50 edit gathers giftable pieces across the collection — and we've written a fuller guide to choosing sterling silver gifts for her.
FAQ
Common questions
What is the most common ring size for women?
Most women's rings fall between US size 5 and 8, with 6 and 7 the most common. If you have to guess without any reference, a size 7 or an adjustable band is the safest choice.
Should I measure my finger in the morning or evening?
Evening. Fingers are slightly fuller at the end of the day, and a ring sized to a morning measurement can feel tight by dinner.
What if my knuckle is wider than the base of my finger?
Size to the knuckle — the ring has to pass over it. A ring that turns a little loosely at the base is far more comfortable than one that won't go on.
Can adjustable rings be resized often?
Adjust them occasionally and gently, not as a daily habit. Set the band to the size you need and let it stay there; repeated back-and-forth bending stresses any metal.
Measured once, the number keeps serving you — and when in doubt, an open band decides for you. Start with the ring collection and see what fits.
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