How to measure ring size at home (accurately)

Ring sizing is easy to get wrong because fingers change size during the day and because most people measure the wrong thing. Two methods work; both take five minutes.

Method 1 — an existing ring

Take a ring that fits the intended finger and measure the inside diameter with a ruler or calipers. Do not measure the outside — that includes the band thickness and gives a size that is too large. Match the millimetres to the chart in our size guide.

Method 2 — paper strip

1. Cut a strip of paper about 10 mm wide.
2. Wrap it around the base of the finger, over the knuckle, and pull it snug — not tight.
3. Mark where the paper overlaps and measure the length in millimetres. That is the circumference.
4. Divide by 3.1416 to get the diameter, then match to the chart.

Why the first measurement is usually wrong

• Temperature. Fingers are smaller in the morning and in cold weather, larger in the evening and after exercise. Measure at the end of the day.
• The knuckle. If the knuckle is wider than the base, size to pass the knuckle. A ring that will not go on is worse than one that spins.
• Band width. A 6 mm band needs a half size more than a 2 mm band on the same finger.

Between sizes?

Go up. It is easier to add sizing beads to a slightly large ring than to stretch a tight one. For wide bands and comfort-fit interiors, go up a quarter to half a size.

When to let us measure

For a custom piece over $1,000, ask for a plastic ring sizer before production — we post them free. For an existing ring, send us the inside diameter in millimetres and we will confirm the size in writing before casting.

Full size chart → · Ask for a free sizer →