Sizing
Ring size chart: mm, US, UK, EU and Indian sizes in one table
Five sizing systems, one finger. The number that never changes is the millimetres, so start there.
Zayr Studio5 min read
Updated
Ring sizes are all based on the inside of the ring, measured either as a diameter or a circumference in millimetres. US sizes go up by about 0.8 mm of diameter per whole size, UK sizes use letters, EU sizes are the inner circumference in millimetres, and Indian sizes, which many Pakistani jewellers also use, are numbered roughly as the circumference minus 40 mm. The chart below converts between all of them.
If you do not know your measurement yet, work that out first with how to measure your ring size at home. This page is the conversion table you use once you have a number.
The full ring size chart
| Inner diameter | Inner circumference | US / Canada | UK / Australia | EU (ISO) | Indian (approx.) |
|---|---|---|---|---|---|
| 14.9 mm | 46.8 mm | 4 | H | 47 | 7 |
| 15.3 mm | 48.0 mm | 4½ | I | 48 | 8 |
| 15.7 mm | 49.3 mm | 5 | J½ | 49½ | 9 |
| 16.1 mm | 50.6 mm | 5½ | K½ | 50½ | 11 |
| 16.5 mm | 51.9 mm | 6 | L½ | 52 | 12 |
| 16.9 mm | 53.1 mm | 6½ | M½ | 53 | 13 |
| 17.3 mm | 54.4 mm | 7 | N½ | 54½ | 14 |
| 17.7 mm | 55.7 mm | 7½ | O½ | 55½ | 16 |
| 18.1 mm | 57.0 mm | 8 | P½ | 57 | 17 |
| 18.5 mm | 58.2 mm | 8½ | Q½ | 58 | 18 |
| 18.9 mm | 59.5 mm | 9 | R½ | 59½ | 19–20 |
| 19.4 mm | 60.8 mm | 9½ | S½ | 61 | 21 |
| 19.8 mm | 62.1 mm | 10 | T½ | 62 | 22 |
| 20.6 mm | 64.6 mm | 11 | V½ | 64½ | 25 |
| 21.4 mm | 67.2 mm | 12 | X½ | 67 | 27 |
| 22.2 mm | 69.7 mm | 13 | Z+1 | 69½ | 30 |
How each system works
- Millimetres: the only universal measurement. Inner diameter is measured straight across the inside of the ring; circumference is the distance around the inside. Circumference equals diameter multiplied by 3.14.
- US and Canada: numbers in quarter and half steps. Each whole size adds about 0.81 mm to the diameter, or about 2.55 mm to the circumference. A half size is roughly 0.4 mm across.
- UK, Australia and New Zealand: letters from A to Z, with half letters in between and Z+1, Z+2 and so on above Z. Each full letter is about 1.25 mm of circumference.
- EU and ISO: simply the inner circumference in millimetres. A size 54 ring measures about 54 mm around the inside.
- Indian, and many Pakistani jewellers: whole numbers, commonly around 1 mm of circumference per size, so size 14 sits near 54 mm around.
Worked examples
- You measured a paper strip at 52 mm. That is closest to 51.9 mm, so US 6, UK L½, EU 52, roughly Indian 12.
- A ring that fits you measures 17.3 mm across the inside. That is US 7, UK N½, EU 54½, roughly Indian 14.
- Your jeweller in Lahore said you are size 16. That is around 56 mm of circumference, so check a US 7½ first.
- You are between two sizes, say 55 mm. Take the larger, US 7½, particularly for a band wider than 5 mm or for summer wear.
Adjusting the number for the ring itself
A chart converts a measurement. It does not know what kind of ring you are buying, and the width of the band changes how a size feels.
| Band width | Adjustment | Why |
|---|---|---|
| Up to 4 mm | Your measured size | Thin bands feel true to size |
| 5–7 mm | Consider a quarter to half size up | More metal in contact with the finger |
| 8 mm and wider | Half size up | Wide bands feel noticeably tight at the knuckle |
| Comfort-fit (domed inside) | Often your usual size, or a quarter down | The rounded interior slips on more easily |
Why sizes feel different in Pakistan's seasons
Fingers are larger in heat and smaller in cold, and the difference across a Pakistani year is real. A ring bought in a Lahore December can feel tight in June, and one sized on a humid Karachi afternoon can spin on a winter morning in Islamabad. Measure at a normal room temperature, in the late afternoon, and if you fall between sizes, favour the larger one for rings you plan to wear through summer. If the ring you end up with is loose, see fixing a ring that is too big.
Common mistakes when converting
- Mixing up diameter and circumference. A 17 mm measurement is a diameter; a 54 mm one is a circumference. If you divide or multiply by 3.14 in the wrong direction, the answer will be absurd, which is at least easy to spot.
- Measuring the outside of a ring instead of the inside. The band's thickness is added twice, and the result can be two or three sizes too big.
- Reading a UK letter as a US number or the other way round when a listing does not say which system it uses. Ask the seller.
- Rounding down when between sizes. The chart steps are close together, and a size that is fractionally tight at the base will not get over the knuckle.
- Using a size from years ago. Fingers change with age, weight, pregnancy and even a change of job, so an old size is a starting point only.
Using the chart when you order
Zayr's women's rings are listed with their sizes, and if a listing's system is not the one you know, this table is how you translate it. Because orders are cash on delivery with a 7-day exchange from delivery for unworn pieces in their original packaging, try a ring on as soon as it arrives rather than waiting for the occasion you bought it for. If you are unsure, message us before ordering with your measurement in millimetres, which removes any confusion over systems.
Every sizing system is just a label for millimetres. When in doubt, drop the label and compare the millimetres.
Common questions
What is my ring size in mm?
Measure the inner diameter of a ring that fits, or the circumference of your finger with a paper strip. A US 6 is about 16.5 mm across and 51.9 mm around; a US 7 is about 17.3 mm across and 54.4 mm around. Each whole US size adds roughly 0.8 mm of diameter.
How do I convert a US ring size to a UK size?
Common conversions are US 5 to UK J½, US 6 to UK L½, US 7 to UK N½, US 8 to UK P½, US 9 to UK R½ and US 10 to UK T½. The UK system uses letters, with half letters between them. Comparing the inner circumference in millimetres is the most reliable way to convert.
What ring size do Pakistani jewellers use?
Many local jewellers use numbered sizes similar to the Indian system, where the number is roughly the inner circumference in millimetres minus 40. For example, size 12 is about 52 mm around. Numbers can vary between jewellers, so ask for the millimetre measurement as well.
What is the most common ring size for women?
For women, US 6 to 7 is the most common range, which is about 51.9 to 54.4 mm in circumference, or roughly Indian 12 to 14. It is a reasonable starting point for a gift, but measuring is always more reliable.
Should I size up for a wide band?
Usually, yes. Bands 5 to 7 mm wide can feel a quarter to half size tighter, and bands 8 mm or wider typically need half a size up. Comfort-fit bands, which are rounded inside, often fit at your normal size.
Ready when you are
Cash on delivery nationwide, exchanges on sizing.