The complete Australian ring size chart โ every AU letter size from F to Z+2 with inside diameter (mm), circumference (mm), and conversions to US, UK, EU, and Japan sizing systems. Includes instant calculator and measuring guide.
Australia (and the UK, New Zealand, and Ireland) uses an alphabetical ring sizing system โ letter sizes from F through to Z+2 for adults. Each letter step represents approximately 1.25 mm of circumference or 0.4 mm of diameter. This is different to the US/Canada numerical system, the European mm-circumference system, and the Japanese/Asian numerical system. Use the full chart and calculator below to find your exact AU size from any measurement or international size.
Find your AU letter size in the first column. The inside diameter is the measurement straight across the inside of the ring. The inside circumference is the full loop measurement around the finger. Half sizes (e.g. Nยฝ) sit between the two whole sizes. โญ rows indicate the most commonly purchased sizes in Australia.
| ๐ฆ๐บ AU Size | Inside Dia. (mm) | Inside Circ. (mm) | ๐บ๐ธ US / CA | ๐ฌ๐ง UK / IE | ๐ช๐บ EU | ๐ฏ๐ต Japan | Typical Wearer |
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Measure between 3โ5 PM when fingers are at their natural everyday size. Avoid measuring in cold weather, after exercise, or first thing in the morning when fingers are at their smallest.
Cut a strip of regular printer paper approximately 1 cm wide by 10 cm long. Do not use elastic, stretchy tape, or rubber band โ only paper, dental floss, or non-stretch thread gives an accurate reading.
Wrap the strip around the base of the intended ring finger (not the knuckle). It should be snug but not tight โ you should be able to slip it off without resistance. Mark the overlap point clearly with a pen.
Unroll the strip and lay it flat against a ruler. Measure from the end of the strip to your pen mark in millimetres. This is your finger circumference in mm.
Take three separate readings and average them. If two readings match and one differs, use the matching two. Averaging removes technique errors and gives a reliable final measurement.
Find your averaged circumference (mm) in the "Inside Circ." column of the chart to identify your AU letter size. If you fall between two sizes, always choose the larger โ a slightly larger ring is easier and cheaper to adjust than a ring that is too small.