Ring Size Chart & Finder

Australian Ring Size Chart (AU, US, UK and mm)

Australia uses the British letter system, so AU and UK sizes are the same. Treat the AU letter as your reference and the US number as a conversion. A half size is only about 0.6mm around the finger, which is why a home measurement is easily half a size out.

Method 1: Measure an Existing Ring

If you have a ring that fits the correct finger, measure the internal diameter in millimetres and match it to the chart above. Place the ring on a ruler and measure from the inside edge to inside edge across the widest point.

Method 2: String or Paper Strip

1. Cut a thin strip of paper or use a piece of non-stretchy string.
2. Wrap it snugly around the base of the finger you want to measure.
3. Mark where the strip overlaps with a pen.
4. Lay it flat and measure the length in millimetres.
5. Match the circumference to the chart above.

Tip: Measure at the end of the day when fingers are at their largest. Avoid measuring when cold, as fingers shrink in lower temperatures.

How Do I Find Their Ring Size Without Asking?

• Borrow a ring they already wear on the same finger of the same hand, and measure its inside diameter. A ring from a different finger, or from the other hand, won't be the same size.
• Ask someone close to them, who may know their size or can borrow a ring for you.
• Order now and size later. Choose "Help Me Later" when you order and we'll confirm the size before your ring is made.

If you guess, most of our designs include one free resize in the first 12 months, so a surprise proposal doesn't have to be a perfect fit on the day.

Does Band Width or Style Change Your Ring Size?

Yes, and it's the most common sizing mistake we see. A wider band feels tighter at the same size, because more metal grips the knuckle, so wide bands usually need sizing up slightly. A comfort fit band, rounded on the inside, slides on more easily and feels looser; many people size down about half a size for one.

So never assume your usual size carries over to a different ring. Get measured for the width and profile you're actually buying. Our wedding ring guide explains band widths and profiles in more detail.

What If the Ring Doesn't Fit?

Most gold and platinum rings can be resized, and most of our designs include one free resize in the first 12 months. The exceptions are worth knowing before you buy: a full eternity band, set with stones all the way round, usually can't be resized, so choose a half eternity if your size might change. Browse our lab-grown diamond engagement rings and wedding bands, all made to order in your size, including half sizes.