A full ring size chart mapping every major sizing standard to the same underlying measurement — inner diameter and circumference in millimeters — so you can convert between US, UK, EU, Japanese, and Australian sizes in one lookup, plus dedicated men's, women's, and printable versions below.
Every size shown in millimeters, centimeters, and inches alongside its US, UK/AU, EU, and Japanese equivalent. Sort any column, or search for a size, mm value, or letter.
| US Size ↕ | UK / AU ↕ | EU ↕ | Japan ↕ | Diameter (mm) ↕ | Diameter (in) ↕ | Circumference (mm) ↕ | Circumference (cm) ↕ |
|---|
Figures are industry-standard approximations compiled from multiple jewelry sizing references. Actual fit can vary by ±0.25 size depending on band width and metal.
The conversion math is identical for everyone — sizing standards don't differentiate by gender. These are simply the size ranges most commonly ordered for men's and women's rings, pulled from the same chart above, so you can jump straight to the relevant rows.
US men's rings most commonly fall between size 8 and 13, reflecting a wider average finger circumference. Wider bands (8mm+), which are more common in men's styles, may need to size up a quarter size for comfortable fit.
| US | UK/AU | Diameter (mm) | Circumference (mm) |
|---|
US women's rings most commonly fall between size 4 and 9. Engagement and wedding rings tend to cluster around size 6, but always measure individually rather than assuming an average fit.
| US | UK/AU | Diameter (mm) | Circumference (mm) |
|---|
Print this page for an at-home reference — it includes a true-to-scale millimeter ruler so you can sanity-check your printer's scaling before trusting the chart.
Print at 100% scale. Hold the ruler below against a physical ruler — if the marks don't line up exactly, your printer scaled the page and this chart will not be accurate.
| US | UK/AU | EU | JP | Diameter (mm) | Circumference (mm) |
|---|
Every screen has a different pixel density, so a millimeter drawn as an image will render at a different physical size on a phone, a laptop, and an external monitor — sometimes off by 20% or more. Rather than publish a static "actual size" graphic, our calculator uses a live calibration step: you match an on-screen ruler to a real one you're holding, so the millimeter measurement is corrected for your exact screen before it's used.
Calibrate My Screen & Measure →Divide the millimeter circumference by 10. For example, a common US size 7 has a circumference of about 54.4mm, which is 5.44cm. The chart above lists both mm and cm directly so you don't need to convert manually.
The average US women's ring size is around 6 to 6.5, while the average US men's ring size is around 9 to 10. These are population averages only — always measure individually before ordering.
Only if your printer is set to 100% scale with "Fit to Page" turned off. Our printable version above includes a millimeter ruler so you can confirm your printout is true to size before measuring against it.
Use an interactive calculator that calibrates to your screen rather than relying on a fixed-size image — our ring size calculator does this in under a minute using a physical ruler for reference.
No — the US uses a numeric scale, the UK and Australia use a letter scale, and both map to the same underlying circumference in millimeters. The chart above converts between all of them using that shared measurement.