A US size 10 ring has an inner diameter of 19.8 mm (0.78 inches) and an inner circumference of 62.2 mm. It is UK T½, EU 62 and India/Japan 21. Size 10 is a common men’s ring size and the upper end of the average men’s range. Confirm your size on screen with the online ring sizer.
| US / Canada size | 10 |
|---|---|
| Inner diameter | 19.8 mm = 0.780 in |
| Inner circumference | 62.2 mm = 2.45 in |
| UK / Australia | T½ |
| EU / ISO / Germany | 62 |
| India / Japan / China | 21 |
| Switzerland | 22 |
| Half size smaller | US 9.5 (19.4 mm) |
| Half size larger | US 10.5 (20.2 mm) |
Who wears size 10?
- Men with average to large hands on the ring finger; together with 9, size 10 is the most common men’s size.
- Men’s middle finger when the ring finger is 9–9.5.
- Women’s thumb rings for larger hands.
Checking size 10 at home
- Measure the inside of a ring that fits: 19.6–20.0 mm is size 10.
- Measure around the finger base with paper: 61.6–62.8 mm is size 10.
- Or calibrate the ring sizer with a bank card and match the ring to the circle.
Worked example
David measures his finger with a paper strip and gets 63 mm. 63 ÷ 3.1416 = 20.05 mm diameter, between US 10 (19.8 mm) and 10.5 (20.2 mm). His knuckle is large, so he chooses 10.5 in a 6 mm comfort-fit band. If his knuckle were small, a size 10 would sit more securely.
Size 10 conversions
| System | Size 10 equals |
|---|---|
| UK / Australia | T½ |
| EU / ISO | 62 |
| Switzerland | 22 |
| India / Pakistan / Japan | 21 |
| Inner diameter | 19.8 mm / 0.78 in |
10 vs 9.5 vs 10.5
US 9.5 is 19.4 mm, 10 is 19.8 mm and 10.5 is 20.2 mm. Fingers change by up to half a size between morning and evening, and between winter and summer. A ring that is fine in the evening in summer but loose on a cold morning is the right size; a ring that is tight in the evening is too small. One size down is size 9.
Wide bands at size 10
Many men’s bands are 6–8 mm wide. For a flat 8 mm band, a man who measures exactly 10 often needs 10.5. Signet rings with a heavy top can rotate if they are loose, so for those a snug fit at the exact size is better.
Buying a size 10
- Size 10 is widely stocked in men’s rings.
- In Europe, look for size 62; in the UK, T or T½.
- For non-resizable materials (tungsten, ceramic), measure twice and consider band width before ordering.
Measuring a man’s finger for size 10
Men’s knuckles are often much larger than the base of the finger, which makes string measurements tricky. Measure both the base and the knuckle, and choose a size between them. A ring that fits only the base will not go on; a ring sized to the knuckle may spin. A paper strip around the knuckle of 63–64 mm with a base of 61–62 mm points to size 10 or 10.5.
Not sure of your ring size? Measure it on your phone screen in 30 seconds.
Open the free ring sizer →All sizes: ring size in mm and the full ring size chart.
Frequently asked questions
What is a size 10 ring in mm?
A US size 10 ring is 19.8 mm in inner diameter and 62.2 mm in inner circumference.
What is size 10 ring in UK?
US 10 is UK T½.
Is size 10 big for a man?
No. Size 10 is within the most common men’s range of 9 to 10.
What is size 10 ring in inches?
About 0.78 inches in inner diameter and 2.45 inches around the inside.
What is size 10 ring in EU?
EU 62, about 62 mm inner circumference.