Ring Size Guide

How to use this guide

Before proceeding, use a ruler to confirm the printed paper size in the box to the right.

Pull tightly. The sizer must fit snugly to produce an accurate size.

Measure your finger at the time of the day when it will be at its largest, this is usually at the end of the day.

Bands and rings overs 5mm in width may fit your finger more tightly than rings of the same size in narrower widths

Measure a current ring

  1. Choose a ring that correctly fits the finger you are purchasing the ring for. In the United States the engagement ring and wedding band are most commonly worn on the ring finger of the left hand.
  2. Lay the ring over each of the size circles below until you are able to closely match the inside edge of the ring to one of the circles on the guide.
  3. If the ring falls between two of the sizes, order the quarter size in the middle.

Ring size conversion chart

Measurements are equivalent to the interior circumference of the corresponding ring size.


Phone a friend:Her friend might have bought her a ring before. It’s also very likely the topic of engagement rings could have popped up in a conversation with her friends.

Borrow a ring:If your partner wears rings, take one of her rings to your local jewellers and get it measured, it’s tricky to secretly do this but also a pretty accurate method.

Sleeping Beauty:If your partner is heavy sleeper, you’re in luck! While she blissfully slumbers, wrap a piece of paper or string around her ring finger to get the size.

Trace it:When you get a chance take one of her rings and place it on a paper, draw a circle on inside of the ring and you’ve got her ring size. Pretty simple.

The average finger sizeis a 6 to 6.5 for women, and 9 to 10 for men. When no other information is available to you, selecting one of these sizes is your best choice.


  • Our dominant hands are generally slightly larger – make sure you measure for her left!
  • Rings with wider bands will fit a bit tighter. If you plan to measure one of her rings, try to measure one with a similar width as the ring you want to purchase.
  • If it comes down to guessing, err on the large side. You want the ring to be able to slip onto her finger when you’re proposing!

All labgrowndiamond Inc rings are specified in standard US sizes. If you are looking for Australia, New Zealand, US, or Ireland ring sizes, view our ring size conversion chart.

US & Canada Australia, New Zealand, UK & Ireland
3 F
3 1/4 F 1/2
3 1/2 G
3 3/4 G 1/2
4 H
4 1/4 H 1/2
4 1/2 I
4 3/4 J
5 J 1/2
5 1/4 K
5 1/2 K 1/2
5 3/4 L
6 L 1/2
6 1/4 M
6 1/2 M 1/2
6 3/4 N
7 N 1/2
7 1/4 O
7 1/2 O 1/2
7 3/4 P
8 P 1/2
8 1/4 Q
8 1/2 Q 1/2
8 3/4 R
9 R 1/2
9 1/4 S
9 1/2 S 1/2
9 3/4 T
10 T 1/2
10 1/4 U
10 1/2 U 1/2
10 3/4 V
11 V 1/2
11 1/4 W
11 1/2 W 1/2
11 3/4 X
12 X 1/2
12 1/4 Y
12 1/2 Z