How to get your ring size right — the first time
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We've all been there. Someone measures their finger with a piece of string, checks a chart online, orders a size 8 — and gets a ring that either spins like a hula hoop or won't get past the knuckle. Ring sizing sounds so simple. It really isn't. Here's what you actually need to know.
You can view our comprehensive Ring Sizing Chart here.
Important
Tungsten and titanium rings cannot be resized. Ever. The material is too hard. This means getting your size right before you order is not optional — it is the only option. Please read this whole post before you buy.
The string method. Just don't.
Wrapping a piece of string or paper around your finger and measuring the length is probably the most popular DIY sizing method on the internet. It's also one of the least reliable.
The problem
String stretches. Paper twists. You pull it too tight because you think "snug" means as tight as possible. Then you measure with a ruler that may or may not be accurate, on a finger that was cold this morning but will be swollen by this evening. That's four opportunities for error before you've even looked at a chart.
Your finger size changes throughout the day — fingers are smaller in the morning and larger in the evening, and they swell in heat. A ring sized at 9am in winter may feel too tight on a summer afternoon. If you must measure at home, do it in the evening when your fingers are at their largest.
Measuring across an existing ring with a ruler. Also don't.
This one trips people up all the time — it looks accurate. It isn't.
The problem
When you place a ruler across a ring, you are measuring the outer diameter — the full width of the ring including the band on both sides. But ring sizing is based on inner diameter: the size of the actual hole the finger goes through. A typical ring band adds 1–2mm of thickness on each side. That means your outer measurement could be 2–4mm too large, which translates to one or two full sizes off.
So if your husband's ring measures 21mm across with a ruler, the inner diameter might actually be closer to 19.4mm — which is a size 9.5, not an 11. On a ring that cannot be resized, that is a very expensive mistake.
If you are using an existing ring to size from, you need to measure the inner diameter — the space inside the ring — not the full width. Use a vernier calliper with inside jaws for this. A ruler will not give you an accurate inner measurement.
Tungsten and titanium rings are not the same as silver
This is the part most people don't know, and it matters a lot.
Silver rings are typically flat on the inside — the inner surface sits flush against your finger. When you measure a silver ring's inner diameter, what you measure is what you get.
Comfort fit — what it means
Tungsten and titanium rings are almost always comfort fit. This means the inside of the band is gently curved — domed, like the inside of a barrel. The highest point of that dome is what touches your finger, not the full inner edge of the ring.
This makes comfort fit rings easier to slide on and off, and far more comfortable to wear. But it also means the ring feels slightly looser than a flat-band ring of the same stated size — because less of the inner surface is in contact with your finger.
Our ring sizing chart lists inner diameter measurements taken with a vernier calliper on the inside of the ring, accounting for the comfort fit curvature. So when our chart says 20.2mm for a size 10.5, that is the true inner measurement — not the outer width with a ruler thrown across it.
So what should you actually do?
The right way
Get sized at a jeweller. It takes five minutes, it's usually free, and it removes all the guesswork. A jeweller uses a ring mandrel — a tapered metal stick with sizes marked on it — to give you an accurate size in your local sizing system. This is the only method we genuinely trust.
If you can't get to a jeweller, the next best option is to use an existing ring you wear on that finger — but measure the inner diameter properly, with a vernier calliper using the inside jaws. Place the jaws inside the ring, open them until they touch the inner edges, and read the measurement. Then use our chart to find your size.
A quick word about our chart
Our ring sizing chart includes circumference, inner diameter, UK jeweller size, and US size. The diameter measurements in our chart are taken with a vernier calliper on the inside of the ring. They are inner measurements — not ruler-across-the-outside measurements. They also account for the comfort fit profile of our tungsten and titanium rings.
Bottom line
If a number on our chart doesn't match what you measured with a ruler placed on top of a ring, that is why. Trust the vernier. Trust the jeweller. And make sure you fit a tungsten ring in the same width you're ordering (8mm, 6mm, 4mm) when sizing.
Still not sure?
WhatsApp us directly — we would rather spend five minutes helping you get the right size than have you receive a ring that doesn't fit. Click here to chat to us on WhatsApp.