Ring Size Standards Overview

Different regions use different ring size standards. Conversions are approximate and can vary by manufacturer.

• US/CA: Numeric scale with half sizes (e.g., 6, 6.5).
• UK/AU: Alphabetic scale with half-steps (e.g., M, M½).
• EU: Typically inner circumference in mm (e.g., 52, 53).
• JP/SG: Numeric scale (e.g., 12, 13).
• HK/CH: Local numeric scales that may differ from JP.

• Manufacturing tolerances and brand-specific charts.
• Ring width and profile (wide bands feel tighter).
• Finger changes with temperature, time of day, and hydration.
• Rounding between systems and half/quarter sizes.

• Measure at the end of the day when fingers are warm.
• Calibrate your screen before measuring for best accuracy.
• If between sizes, consider comfort-fit and band width.
• When possible, confirm with a jeweler or a physical sizer.

Our tools provide a best-effort estimate based on international conversions. Use it as guidance, not a guaranteed fit.