From the Anny's workshop
Jewellery Tools and Size Charts
Find your size, compare stones or check a piece you love.
A little guidance, at your fingertips
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Choose a tool to get started.
Find your fit
Ring size converter
Compare AU/UK, US and EU sizes or convert a ring measurement.
Find my ring sizeFind your fit
Printable ring sizer
Print a true-scale sizer: wrap the strip round your finger or match a ring you own.
Print my ring sizerWhat it costs
Diamond price guide
What a diamond costs by shape and carat, natural vs lab-grown, or what your budget buys.
See diamond pricesRead your jewellery
Gold & silver stamp chart
What 375, 585, 750, 925 or PT950 on your jewellery means.
Decode my stamp
For the workbench
Specialist estimates for people with the measurements and material details to hand.
Diamond size & carat calculator
Millimetres to carat for one stone, or the total weight of a bracelet or halo.
Chain gauge to mm
Turn a chain gauge into a typical width in mm, by style.
Gemstone carat calculator
Estimate a known coloured gemstone’s weight from its measurements.
Metal weight converter
Convert a weight between metals, or read our comparison chart.
Find your everyday fit
Australian ring size converter
Choose an Australian or UK letter size, or enter a millimetre measurement, to compare AU/UK, US and EU ring sizes. Australia and the UK share one alphabetical scale.
View the full ring size comparison chartSizes run G to Z+6, including half sizes.
AU/UK, US and EU ring size chart
Compare Australian and UK sizes with approximate US and EU equivalents, plus inside diameter and circumference in millimetres. Measure across the inside of a ring that already fits — not around your finger — and read down the diameter column.
| AU / UK | US (approx.) | EU (approx.) | Inside diameter | Inside circumference |
|---|---|---|---|---|
| G | 3.5 | 46 | 14.5 mm | 45.5 mm |
| G½ | 3.75 | 46 | 14.7 mm | 46.1 mm |
| H | 4 | 47 | 14.9 mm | 46.8 mm |
| H½ | 4.25 | 47 | 15.1 mm | 47.4 mm |
| I | 4.5 | 48 | 15.3 mm | 48.0 mm |
| I½ | 4.75 | 49 | 15.5 mm | 48.7 mm |
| J | 5 | 49 | 15.7 mm | 49.3 mm |
| J½ | 5.25 | 50 | 15.9 mm | 50.0 mm |
| K | 5.5 | 51 | 16.1 mm | 50.6 mm |
| K½ | 5.75 | 51 | 16.3 mm | 51.2 mm |
| L | 6 | 52 | 16.5 mm | 51.9 mm |
| L½ | 6.25 | 53 | 16.7 mm | 52.5 mm |
| M | 6.5 | 53 | 16.9 mm | 53.1 mm |
| M½ | 6.75 | 54 | 17.1 mm | 53.8 mm |
| N | 7 | 54 | 17.3 mm | 54.4 mm |
| N½ | 7.25 | 55 | 17.5 mm | 55.1 mm |
| O | 7.5 | 56 | 17.7 mm | 55.7 mm |
| O½ | 7.75 | 56 | 17.9 mm | 56.3 mm |
| P | 8 | 57 | 18.1 mm | 57.0 mm |
| P½ | 8.25 | 58 | 18.3 mm | 57.6 mm |
| Q | 8.5 | 58 | 18.6 mm | 58.3 mm |
| Q½ | 8.75 | 59 | 18.7 mm | 58.9 mm |
| R | 9 | 60 | 18.9 mm | 59.5 mm |
| R½ | 9.25 | 60 | 19.2 mm | 60.2 mm |
| S | 9.5 | 61 | 19.4 mm | 60.8 mm |
| S½ | 9.75 | 61 | 19.5 mm | 61.4 mm |
| T | 10 | 62 | 19.8 mm | 62.1 mm |
| T½ | 10.25 | 63 | 20.0 mm | 62.7 mm |
| U | 10.5 | 63 | 20.2 mm | 63.4 mm |
| U½ | 10.75 | 64 | 20.4 mm | 64.0 mm |
| V | 11 | 65 | 20.6 mm | 64.6 mm |
| V½ | 11.25 | 65 | 20.8 mm | 65.3 mm |
| W | 11.5 | 66 | 21.0 mm | 65.9 mm |
| W½ | 11.75 | 67 | 21.2 mm | 66.6 mm |
| X | 12 | 67 | 21.4 mm | 67.2 mm |
| X½ | 12.25 | 68 | 21.6 mm | 67.8 mm |
| Y | 12.5 | 69 | 21.8 mm | 68.5 mm |
| Y½ | 12.75 | 69 | 22.0 mm | 69.1 mm |
| Z | 13 | 70 | 22.2 mm | 69.7 mm |
| Z½ | 13.25 | 70 | 22.4 mm | 70.4 mm |
| Z+1 | 13.5 | 71 | 22.6 mm | 71.0 mm |
| Z+1½ | 13.75 | 72 | 22.8 mm | 71.6 mm |
| Z+2 | 14 | 72 | 23.0 mm | 72.3 mm |
| Z+2½ | 14.25 | 73 | 23.2 mm | 72.9 mm |
| Z+3 | 14.5 | 74 | 23.4 mm | 73.5 mm |
| Z+3½ | 14.75 | 74 | 23.6 mm | 74.2 mm |
| Z+4 | 15 | 75 | 23.8 mm | 74.8 mm |
| Z+4½ | 15.25 | 76 | 24.0 mm | 75.5 mm |
| Z+5 | 15.5 | 76 | 24.2 mm | 76.1 mm |
| Z+5½ | 15.75 | 77 | 24.4 mm | 76.7 mm |
| Z+6 | 16 | 77 | 24.6 mm | 77.4 mm |
US and EU equivalents are approximate: US sizes are rounded to the nearest quarter size and EU sizes to the nearest whole millimetre of inside circumference. Confirm your fit with a jeweller before ordering.
We make rings to order from size H to Z+2. The chart runs wider than that for reference — if your size falls outside the range we make, get in touch and we will work out what is possible.
Sizes are quoted by inside circumference per ISO 8653; the diameter column is calculated from it. Reviewed 2026-08-28.
Other reference charts
Sizing a stone rather than a finger? Our diamond size chart converts millimetres to carat weight and back across every shape we sell, measured from our own certified stones. For what a repair or resize costs, see the repair price guide. Ring too tight to come off? Here’s what to try.
Getting an accurate measurement
Fingers are not a fixed size. They swell in heat and after exercise, shrink in the cold, and most people's dominant hand runs slightly larger. Measure in the afternoon at normal room temperature, when your hands are neither hot nor cold, and take the reading two or three times rather than trusting a single one.
Band width matters more than people expect. A wide band sits against more of the finger and feels tighter than a narrow one at the same measured size, so for anything above about 6 mm wide it is worth going up a half size. Knuckles matter too — if yours are noticeably larger than the base of the finger, the ring has to pass the knuckle and then sit without spinning, which is a fitting judgement rather than a measurement.
For anything you intend to wear every day, and for engagement rings in particular, come in and be sized properly on a professional mandrel. It takes a minute and removes the guesswork. If a ring you already own no longer fits, our workshop can resize it — see jewellery repairs and resizing for what that involves and what it costs.
Common questions
Is an Australian ring size the same as a UK ring size?
Yes. Australia and the UK use the same alphabetical scale, so a size N in Melbourne is a size N in London. The letters map to a physical measurement — the inside circumference of the band in millimetres — which is what a jeweller actually works to.How do I measure my ring size at home?
Measure a ring that already fits the right finger, not the finger itself. Lay it flat and measure straight across the inside of the band in millimetres — that is the inside diameter. Enter it in the converter above and it will return the closest Australian size. Fingers change size through the day and with temperature, so measure in the afternoon at normal room temperature for the most representative result.What if my measurement falls between two ring sizes?
Treat the conversion as a starting point and have a jeweller check the fit when you fall between sizes. Band width, finger shape and the design affect comfort. Try a sizer with a similar width to your intended ring. Some ring designs cannot be resized, so confirm before choosing.Can Anny's resize a ring I already own?
Yes. Frankston handles all services, including repairs, valuations, engraving, remodelling, engagement rings and wedding rings. Our Frankston workshop resizes rings up and down in gold, white gold, rose gold, platinum and silver, whether or not the piece was bought from us. Bring it to the Frankston workshop for a free inspection and we will quote the work the same visit. Email us before visiting Collins Street for engagement-ring and wedding-ring consultations. Please wait for our email confirmation before coming in.
Reviewed