Find your ring size
What does US 4 mean?
US identifies the American sizing scale; 4 is the size number, not a measurement in millimetres. US 4 is approximately 14.9 mm across the inside of the ring and 46.8 mm around the inside. A higher US number means a larger ring. The same scale applies to all genders.
A ring size is separate from a diamond’s carat weight (ct) and gold purity (10k, 14k or 18k). European systems differ: French/EU sizes commonly refer approximately to inner circumference in millimetres, while some systems use inner diameter. Always compare the measurements, not just the size number.
US sizes and measurements
US Inside diameter (mm) Inside circumference (mm)
US 4 14.9 46.8 US 4.5 15.3 48.0 US 5 15.7 49.3 US 5.5 16.1 50.6 US 6 16.5 51.9 US 6.5 16.9 53.1 US 7 17.3 54.4 US 7.5 17.7 55.7 US 8 18.1 57.0 US 8.5 18.5 58.3 US 9 18.9 59.5 US 9.5 19.4 60.8 US 10 19.8 62.1 US 10.5 20.2 63.4 US 11 20.6 64.6 US 11.5 21.0 65.9 US 12 21.4 67.2
Measurements are approximate and rounded; conversion charts can vary slightly. For example, US 7 is about 17.3 mm in diameter and 54.4 mm in circumference — close to an EU circumference size of 54. The illustrations are explanatory, not a screen-sized measuring tool.
Method 1 · Measure a ring that fits
Inside diameter, measured across the centre
Choose a round ring that fits the same finger on the same hand comfortably. A ring worn on another finger may give the wrong result. Lay it flat and measure straight across the centre from one inside edge to the opposite inside edge, using a ruler with millimetres or callipers. Exclude the metal band. Match this inside diameter to the table. For example, an inside diameter of about 18.1 mm corresponds to US 8. Method 2 · Measure your finger
Use a narrow strip of paper or a flexible, non-stretch measuring tape. Wrap it around the base of the intended finger; it should touch the skin without squeezing. Mark where the ends meet, lay the strip flat and measure to the mark in millimetres. This is circumference, not diameter; use the circumference column directly. Check that the loop can pass over the knuckle with gentle resistance. Repeat the measurement a few times; if the knuckle is much wider than the finger base, have a jeweller check the fit. For a comfortable fit
Measure near the end of the day at a comfortable room temperature. Cold fingers, heat, exercise or swelling can change the result. Measure the correct hand. If you fall between two sizes, try the larger half size. A wide band or several stacked rings can feel tighter; confirm the fit with a sizer of similar width rather than automatically adding a full size. A good fit stays in place but passes over the knuckle without force. For the most reliable result, ask a jeweller to measure you with a ring sizer, especially for wide or full-eternity bands. Still unsure? Contact LENELIS before ordering. Share your measurement in millimetres and whether it is diameter or circumference.
Ask for sizing help ↗
