Determining your ring size can be challenging but is crucial to the design and manufacturing process. Due to a range of factors, one’s ring size can drastically change. However, with various techniques available, you can be sure to find the best fit!
The size of one’s finger is measured in whole and ½ numbers, which correspond to a letter of the alphabet. Leading edge, centre and trailing edge are the three standard terms used when sizing a ring. As rings come in various widths, it can prove not easy to size the ring as it can sometimes include multiple sizes. For example, a ring with a width of 3mm would be measured based on the size recorded at the centre. The leading and trailing edge would be irrelevant as the ring is not wide enough to cover more than one size. However, a ring with a width of 5mm requires an extra ½ size due to surface grip plus an additional ½ size from the centre for the leading edge measurement and deduct a ½ size from the centre for the trailing edge measurement. Below is a ring size conversion chart detailing the differences between men’s and women’s sizes and what numerical value corresponds to what letter of the alphabet.
| Comparison of Ring Sizes | Circum | Diameter | |||||
| USA | UK/NZ/AUS | Japan | Germany | France | Swiss | mm | mm |
| Ladies Sizes | |||||||
| 2.0 | D | 2 | 13.25 | 41.25 | 1.50 | 41.5 | 13.2 |
| 2.5 | E | 3 | 13.75 | 42.75 | 2.75 | 42.7 | 13.6 |
| 3.0 | F | 4 | 14.00 | 44.00 | 4.00 | 44.0 | 14 |
| 3.5 | G | 5 | 14.50 | 15.25 | 5.25 | 45.2 | 14.4 |
| 4.0 | H | 7 | 15.00 | 16.50 | 7.75 | 46.5 | 14.8 |
| 4.5 | I | 8 | 15.25 | 48.00 | 8.75 | 47.8 | 15.2 |
| 5.0 | J | 9 | 15.75 | 50.00 | 9.00 | 49.0 | 15.6 |
| 5.5 | K | 10 | 16.00 | 51.75 | 11.75 | 50.3 | 16 |
| 6.0 | L | 12 | 16.50 | 52.75 | 12.75 | 51.5 | 16.4 |
| 6.5 | M | 13 | 17.00 | 54.00 | 14.00 | 52.8 | 16.8 |
| 7.0 | N | 14 | 17.25 | 55.25 | 16.25 | 54.0 | 17.2 |
| 7.5 | O | 15 | 17.75 | 56.50 | 16.50 | 55.3 | 17.6 |
| 8.0 | P | 16 | 18.00 | 57.75 | 17.75 | 56.6 | 18 |
| 8.5 | Q | 17 | 18.50 | 58.00 | 19.00 | 57.8 | 18.4 |
| 9.0 | R | 18 | 19.00 | 60.00 | 20.25 | 59.1 | 18.8 |
| Gents Sizes | |||||||
| 9.5 | S | 19 | 19.50 | 61.25 | 21.50 | 60.3 | 19.2 |
| 10.0 | T | 20 | 20.00 | 62.00 | 22.50 | 61.6 | 19.6 |
| 10.5 | U | 22 | 20.25 | 63.25 | 23.00 | 62.8 | 20 |
| 11.0 | V | 23 | 20.75 | 65.00 | 24.00 | 64.1 | 20.4 |
| 11.5 | W | 24 | 21.00 | 66.0 | 26.00 | 65.3 | 20.8 |
| 12.0 | X | 25 | 21.25 | 67.50 | 27.50 | 66.6 | 21.2 |
| 12.5 | Y | 26 | 21.75 | 68.75 | 28.75 | 67.8 | 21.6 |
| 13.0 | Z | 27 | 22.00 | 69.00 | 30.00 | 69.1 | 22 |
| 13.5 | Z + 1 | – | – | – | – | – | – |
| 14.0 | Z + 2 | – | – | – | – | – | – |
| 14.5 | Z + 3 | – | – | – | – | – | – |
Various internationally recognised and used tools assist with this process. One of these is a mandrel, as seen in the picture below. A mandrel is a consistently accurate way of determining a ring size and allows one to quickly identify the leading edge, centre, and trailing edge measurements. The Wheatsheaf mandrel is the universally accepted sizing stick.
Unfortunately, getting a ring stuck on your finger is a common problem when trying ring sizes. However, should this happen, ways to get the ring off include soaking your hand in cold water to reduce your finger size, washing your hands with either soap or dishwashing liquid, or using moisturiser or hand cream to ease the ring.
At Polished Diamonds Jewellery Design, we have various tools to determine your ring size best. If you are unsure, need a ring resized or are designing a new engagement or wedding ring, please get in touch with us; we’d love to help and are confident in our ring sizing abilities! However, titanium rings cannot be resized as the metal will not melt. Thus, if you require a titanium ring, getting the most accurate ring size is crucial, as there is no room for error. In comparison, gold and platinum rings can be resized as the metal can be melted down; thus, adjustments can be made if a ring size needs correcting.