Ring size chart: inside diameter for US, EU and Turkish sizes
A ring size describes the hole the finger goes through. US, European (EU) and Turkish (TR) sizes describe the same inside diameter with different numbers. When you model a ring, the inside diameter is the only number that matters: the shank thickness is added outward.
US ring sizes
The values below are the inside diameters the Kumpix engine uses when it builds a ring. US sizes go up in half sizes; for a size not in the table, inside diameter = 11.63 + 0.8128 × size.
| Size | Inside diameter (mm) | Inside circumference (mm) |
|---|---|---|
| US 3 | 14.10 | 44.30 |
| US 3.5 | 14.50 | 45.55 |
| US 4 | 14.90 | 46.81 |
| US 4.5 | 15.30 | 48.07 |
| US 5 | 15.70 | 49.32 |
| US 5.5 | 16.10 | 50.58 |
| US 6 | 16.51 | 51.87 |
| US 6.5 | 16.92 | 53.16 |
| US 7 | 17.32 | 54.41 |
| US 7.5 | 17.75 | 55.76 |
| US 8 | 18.14 | 56.99 |
| US 8.5 | 18.53 | 58.21 |
| US 9 | 18.93 | 59.47 |
| US 9.5 | 19.41 | 60.98 |
| US 10 | 19.84 | 62.33 |
| US 10.5 | 20.20 | 63.46 |
| US 11 | 20.68 | 64.97 |
| US 11.5 | 21.08 | 66.22 |
| US 12 | 21.49 | 67.51 |
European (EU) ring sizes
The European size is simply the inside circumference in millimeters, so inside diameter = size ÷ π.
| Size | Inside diameter (mm) | Inside circumference (mm) |
|---|---|---|
| EU 48 | 15.28 | 48.00 |
| EU 50 | 15.92 | 50.01 |
| EU 52 | 16.55 | 51.99 |
| EU 54 | 17.19 | 54.00 |
| EU 56 | 17.83 | 56.01 |
| EU 58 | 18.46 | 57.99 |
| EU 60 | 19.10 | 60.00 |
| EU 62 | 19.74 | 62.02 |
Turkish (TR) ring sizes
Turkish sizes are common in orders from Turkey and the Middle East. For a Turkish size not in the table, the inside circumference is taken as the size plus 40, so inside diameter = (size + 40) ÷ π.
| Size | Inside diameter (mm) | Inside circumference (mm) |
|---|---|---|
| TR 8 | 15.30 | 48.07 |
| TR 9 | 15.60 | 49.01 |
| TR 10 | 15.90 | 49.95 |
| TR 11 | 16.20 | 50.89 |
| TR 12 | 16.50 | 51.84 |
| TR 13 | 16.90 | 53.09 |
| TR 14 | 17.20 | 54.04 |
| TR 15 | 17.50 | 54.98 |
| TR 16 | 17.80 | 55.92 |
| TR 17 | 18.15 | 57.02 |
| TR 18 | 18.50 | 58.12 |
| TR 19 | 18.80 | 59.06 |
| TR 20 | 19.10 | 60.00 |
| TR 21 | 19.42 | 61.01 |
| TR 22 | 19.80 | 62.20 |
| TR 23 | 20.05 | 62.99 |
| TR 24 | 20.40 | 64.09 |
| TR 25 | 20.69 | 65.00 |
| TR 26 | 21.00 | 65.97 |
Ring sizes in Kumpix
In ring templates and in AI orders you can enter the size as US, EU or TR; Kumpix converts it to an inside diameter and shows the measured inside diameter of the model. When you change the size, the shank, the stones and the weight are recalculated.
To start from a ready model, see the ring templates and the wedding band templates. How much the same ring weighs in different karats is covered in gold weight by karat.