US ring size 13 in UK, Europe and India
US ring size 13 is UK size Z½, European (ISO) size 70.2 and Indian/Japanese size 27. That is an inside diameter of 22.33 mm and an inside circumference of 70.15 mm.
How to check this is your size
The surest way is to measure a ring that already fits the right finger. Lay it flat and measure straight across the inside of the band. If it reads about 22.33 mm (0.879 in), you are a US 13.
If you have no ring to hand, wrap a strip of paper around the base of the finger, mark where it overlaps, and measure the length. About 70.15 mm (2.76 in) means US 13. Measure at the end of the day, when fingers are at their largest — a ring sized on a cold morning will feel tight by evening.
US 13 is a large size, usually a man's ring finger or a thumb ring.
US 13 and its neighbors
| US | UK / AU | Europe | India / Japan | Diameter | Circumference |
|---|---|---|---|---|---|
| 11.5 | W½ | 66.2 | 24 | 21.08 mm | 66.22 mm |
| 12 | X½ | 67.5 | 25 | 21.49 mm | 67.51 mm |
| 12.5 | Y½ | 68.8 | 26 | 21.89 mm | 68.77 mm |
| 13 | Z½ | 70.2 | 27 | 22.33 mm | 70.15 mm |
The full chart covers every size from US 3 to US 16 in all five systems.
Adjusting for the band
A wide band touches more of the finger and feels tighter at the same measurement, and a comfort-fit band (domed on the inside) feels looser. For a finger that measures 70.15 mm:
| Band | Order | ||
|---|---|---|---|
| Narrow band, under 4 mm | US 13 | UK Z½ | EU 70.2 |
What a plain band in this size weighs
Useful if you are buying by weight or checking a quote. A solid band 1.6 mm thick at US 13, with the metal alone valued at today's spot price:
| Band | Weight | Metal value today |
|---|---|---|
| 2 mm 14K | 3.15 g | $230 |
| 2 mm 18K | 3.73 g | $349 |
| 2 mm Platinum | 4.84 g | $213 |
| 4 mm 14K | 6.3 g | $459 |
| 4 mm 18K | 7.46 g | $697 |
| 4 mm Platinum | 9.67 g | $425 |
| 6 mm 14K | 9.45 g | $689 |
| 6 mm 18K | 11.19 g | $1,046 |
| 6 mm Platinum | 14.51 g | $638 |
A jeweler's price is well above the metal value — it carries the making, the finish and the margin — but the metal figure is the floor the piece can never fall below, and the number a scrap buyer starts from.
Measure it yourself, right now
Lay a ring on your screen and match it against circles drawn true to life, calibrated against any bank card.
Open the ring sizer