HomeCalcPro — 專案計算詳細報告
Tool: Ring Size Converter — 免費線上計算機 | HomeCalcPro | 列印時間:
Ring Size Converter — 免費線上計算機 | HomeCalcPro
Ring Size Converter精準試算，提供行業標準公式與即時測算結果。
Inputs & Settings
Instant Conversion & Output
Ring Sizing Conversion Formula (ISO 8653)
Transparent mathematical methodology explained in plain English.
US Size = (Circumference mm - 36.6) / 2.55 | Inside Diameter mm = Circumference mm / πInternational standard ISO 8653 defines ring sizes based on inner circumference in millimeters (e.g. European Size 52 = exactly 52 mm inside circumference).
Variables Explained:
- Measurement Input: Finger Circumference (mm), Inside Diameter (mm), or US Size.
US Size 7 Ring Converted to European mm and UK Letter
Converting standard US ring size to international jewelry scales.
- Inside Circumference: (7.0 × 2.55) + 36.6 = 54.45 mm (~54.5 mm).
- Inside Diameter: 54.45 / π = 17.33 mm.
- European / ISO Standard: Size 54.
- UK & Australia Letter Equivalent: Size N (or N 1/2).
常見問題解答 (FAQ): Ring Size Converter
Click any question below to expand quick answers, formulas, and expert tips.
What is the most common women's and men's ring size in the US?
The average US women's ring size is Size 6 to 7 (approx 16.5–17.3 mm diameter), and the average US men's ring size is Size 9 to 10 (approx 19.0–19.8 mm diameter).
When is the best time of day to measure your ring size?
Measure your fingers at the end of the day when hands are warm; cold temperatures shrink finger diameter by up to half a ring size.