Here are some tips to find out your ring size:

• Measure your finger in warm temperatures at the end of the day.
• If your knuckle is a lot larger than the base of your finger, you can either measure both the base of your finger and your knuckle and select a size in between the two, or use the method below

Measure your finger and compare to the chart:

1. Find a piece of non-stretchy string about 6 inches long, or a strip of paper about 6 inches long and a quarter inch wide.

2. Wrap it well around the base of your finger.

3. Using a pen, mark the point on the string or paper where it folds over, forming a complete circle. This gives you the circumference in millimeters.

4. See the chart below to find your ring size.

U.K. USA / CND Diameter (in millimeters) Circumference (in millimeters)
F 23/4 13.7 43.65
G 31/4 14.3 44.90
H 4 14.7 46.20
I 41/2 15.1 47.45
J 43/4 15.5 48.70
K 51/2 15.9 49.95
L 53/4 16.3 51.25
M 61/4 16.7 52.45
N 63/4 17.1 53.70
O 71/4 17.5 55.00
P 73/4 17.9 56.25
Q 8 18.3 57.50
R 83/4 18.7 58.75
S 91/4 19.1 60.00
T 93/4 19.5 61.25
U 10 19.9 62.50
V 101/2 20.3 63.75
W 11 20.7 65.00
X 111/2 21.1 66.30
Y 12 21.5 67.50
Z 121/2 21.9 68.75

Here are some tips if you're buying the ring as a surprise:

• Ask your partner's mother, sister, or one of her friends if they know her finger size.
• Borrow one of her rings making sure it corresponds to the engagement finger and measure either the diameter or circumference in mm. If you can't find your exact size with the chart at the bottom of this page, simply let us know either the diameter or circumference in mm and we will gladly tell you your ring size.

What if it's not the correct size?

For your peace of mind, Platinum Diamonds provides free lifetime resizing. You can return your item to us at any time for professional resizing. We appreciate that no one likes to be without their ring so we promise to return this to you with a next day delivery service.

More Tips and Guidance

• Your ring size will be about half a size larger on your primary hand (i.e. the hand you write with).