Ring Sizing Guide NZ: How to Find Your Correct Ring Size
Getting the correct ring size is important for comfort, security and the long-term wear of your jewellery. A ring should sit securely on your finger without feeling tight, while still being able to pass over the knuckle with gentle resistance.
In New Zealand, jewellers generally use the UK and Australian alphabetical sizing system to express ring sizes. Because finger size can vary with temperature, time of day, ring width and even which hand you wear the ring on, professional measurement is the most reliable option.
At Polished Diamonds, we can professionally measure your finger at our jewellery design studios in Auckland, Wellington and Christchurch.
How Should a Ring Fit?
A correctly fitted ring should:
- feel comfortable at the base of your finger
- have slight resistance when moving over the knuckle
- not spin excessively during normal wear
- not leave a deep indentation in your finger
- remain secure when your hands are cool
Your fingers naturally change size throughout the day. Warm weather can cause fingers to swell, while colder temperatures may make them slightly smaller. For this reason, avoid determining your size when your hands are unusually hot or cold.
Does Ring Width Affect Ring Size?
Yes. Wider rings generally feel tighter than narrow rings because more metal is in contact with the finger.
For example, a narrow engagement ring may feel comfortable at one size, while a wide wedding band could require a slightly larger size on the same finger.
When choosing wedding rings, we recommend trying the actual or a similar band width rather than relying only on the size of another ring.
When you wear an engagement ring and wedding ring together, their combined width directly influences how comfortably they fit your finger.
How to Measure Your Ring Size
The most accurate method is to have your finger measured professionally using calibrated ring-sizing tools.
Jewellers also use a ring mandrel to measure an existing ring. This is particularly helpful when you already have a ring that fits correctly.
For a surprise engagement ring, borrowing a ring that the person already wears on the correct finger can provide a useful starting point. However, remember that fingers on the left and right hand are not necessarily identical.
If you are designing an engagement ring, we can help establish the appropriate finger size before creating the ring in CAD.
New Zealand Ring Size Conversion Chart
Use the chart below to compare New Zealand, Australian, and UK letter sizes with common international ring-sizing systems.
A conversion chart is useful when purchasing jewellery internationally, but small differences can occur between sizing systems, manufacturers and measuring equipment. For engagement rings, wedding rings and other valuable jewellery, professional measurement is preferable to relying solely on an online conversion chart.
At Polished Diamonds, we use professional Durston UK/NZ ring-sizing mandrels and gauges. Our master jewellers also craft rings in half sizes, providing you with a remarkably precise fit between standard letter sizes. When measuring an existing ring on a tapered mandrel, we take the reading at the centreline of the ring band, rather than from either edge, for a consistent and accurate measurement.
Ring Sizing Chart
| NZ / AU / UK Size | Internal Diameter | Internal Circumference | EU / ISO Approx. | US Approx. |
|---|---|---|---|---|
| A | 12.04 mm | 37.83 mm | 38 | ½ |
| B | 12.44 mm | 39.08 mm | 39 | 1 |
| C | 12.84 mm | 40.32 mm | 40 | 1½ |
| D | 13.23 mm | 41.57 mm | 42 | 2 |
| E | 13.63 mm | 42.82 mm | 43 | 2½ |
| F | 14.03 mm | 44.06 mm | 44 | 3 |
| G | 14.42 mm | 45.31 mm | 45 | 3½ |
| H | 14.82 mm | 46.56 mm | 47 | 4 |
| I | 15.22 mm | 47.80 mm | 48 | 4½ |
| J | 15.61 mm | 49.05 mm | 49 | 5 |
| K | 16.01 mm | 50.30 mm | 50 | 5½ |
| L | 16.41 mm | 51.54 mm | 52 | 6 |
| M | 16.80 mm | 52.79 mm | 53 | 6½ |
| N | 17.20 mm | 54.04 mm | 54 | 7 |
| O | 17.60 mm | 55.28 mm | 55 | 7½ |
| P | 17.99 mm | 56.53 mm | 57 | 8 |
| Q | 18.39 mm | 57.78 mm | 58 | 8½ |
| R | 18.79 mm | 59.02 mm | 59 | 9 |
| S | 19.18 mm | 60.27 mm | 60 | 9½ |
| T | 19.58 mm | 61.52 mm | 62 | 10 |
| U | 19.98 mm | 62.76 mm | 63 | 10½ |
| V | 20.38 mm | 64.01 mm | 64 | 11 |
| W | 20.77 mm | 65.26 mm | 65 | 11½ |
| X | 21.17 mm | 66.50 mm | 67 | 12 |
| Y | 21.57 mm | 67.75 mm | 68 | 12¼–12½ |
| Z | 21.96 mm | 69.00 mm | 69 | 12¾ |
| Z+1 | 22.36 mm | 70.24 mm | 70 | 13¼ |
| Z+2 | 22.76 mm | 71.49 mm | 71 | 13¾ |
| Z+3 | 23.15 mm | 72.74 mm | 73 | 14¼ |
| Z+4 | 23.55 mm | 73.98 mm | 74 | 14¾ |
| Z+5 | 23.95 mm | 75.23 mm | 75 | 15¼ |
| Z+6 | 24.34 mm | 76.48 mm | 76 | 15¾ |
Can an Engagement Ring Be Resized?
Our master bench jewellers can resize most gold and platinum engagement rings, though the ring’s design, setting, and construction dictate how many sizes we can adjust it.
To make a ring larger, a jeweller may carefully add precious metal to the band. To downsize your ring, our master jewellers remove a small section of the band, rejoin the metal, and meticulously refinish and polish the piece.
Some designs, particularly full eternity rings, heavily diamond-set bands and certain alternative metals, can have limited resizing options.
Polished Diamonds provides professional ring resizing through our specialised New Zealand jewellery workshop.
What If I Don’t Know the Ring Size for a Proposal?
Don’t let an uncertain finger size spoil a surprise proposal.
If you can discreetly obtain an existing ring, we may be able to estimate the size. Alternatively, select a size based on your available information and consult our master jewellers to confirm whether we can easily resize that particular design afterwards.
For custom rings, our jewellery designers can also advise on how the design and setting may affect future resizing.
What Should I Do If a Ring Is Stuck on My Finger?
Do not force a tight ring over a swollen knuckle. Allow your hand to cool and try a small amount of soap or lubricant to help the ring move more easily.
Consequently, if your finger swells, aches, turns numb, or changes colour, and you cannot slide the ring off, seek immediate assistance from a medical professional or visit our workshop master jewellers right away.
Professional Ring Sizing in New Zealand
For the most accurate result, visit Polished Diamonds in Auckland, Wellington or Christchurch and have your finger professionally measured.
Whether you are choosing an engagement ring, ordering a wedding band or need an existing ring adjusted, correct sizing helps ensure your jewellery is comfortable, secure and designed for everyday wear.
Ring Sizing FAQs
New Zealand generally uses alphabetical ring sizes based on the UK/Australian sizing system.
Measure when your hands are at a normal, comfortable temperature rather than unusually hot or cold.
Often, yes. Wider bands can feel tighter and may require a slightly larger size than a narrow ring.
Most gold and platinum engagement rings can be resized, although the design and setting can affect how much adjustment is possible.
Polished Diamonds offers professional ring sizing through its Auckland, Wellington and Christchurch jewellery design studios.
Yes. Polished Diamonds can size rings in half sizes where appropriate, allowing a more precise fit between standard UK/NZ letter sizes.
