- ?Lv 41 十年 前最佳解答
Tiffany should use 美國戒圍. If her 圓周係6cm, she should wear size9.5. Actually when you go buy the ring in Tiffany, you can ask the sales and they are usually able to tell you what size you need. Also, with reciept, you can change the ring size if it doesn't fit! No worry at all!
2008-09-05 02:24:31 補充：
Then she should wear 6-3/4size or maybe size7. Actually you can get her diameter by using below method:
2008-09-05 02:24:49 補充：
1/ Wrap a piece of string or a strip of paper around your finger.
2/ Mark the point where the two ends meet.
3/ Measure the string or paper against a ruler to get the circumference of your finger.
4/ Divide that by 3.14 to get the diameter of your finger.
2008-09-05 02:24:58 補充：
And check this website: http://www.onlineconversion.com/ring_size.htm資料來源： Me