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How to find your ideal ring size?

Not sure what ring size to choose? We've created the ultimate guide which will help you make the right decision when it comes to fine jewellery & engagement ring sizes.

Measure the diameter

Use an existing ring that fits well and place it flat on a ruler. Align the inner edge with the scale and measure the inside diameter at the widest point – this value helps you choose the right size.

Step 1

Take a ring that already fits the desired finger well.

Step 2

Place it flat on a ruler.

Step 3

Measure the inner diameter at the widest point and look it up in the table below.

Measure the circumference

Cut a narrow strip of paper and wrap it once around the finger where the ring will sit. Mark the point where the paper meets, then lay it flat on a ruler and measure the length between the marks – this is your finger circumference.

Step 1
Step 1

Cut a narrow strip of paper and wrap it once around the finger.

Step 2

Mark the point where the ends of the paper meet.

Step 3

Lay the strip flat on a ruler and measure the length between the marks. Compare the result with the table below.

Ring size chart

AU US EU Diameter (mm) Circumference (mm)
F 4.5 48 15.3 48
J–K 5 50 16.0 50
K - L 5.5 51 16.2 51
L1/2 6 52 16.5 52
M 6.5 53 16.9 53
N 7 54 17.2 54
O - P 7.5 56 17.8 56
P 8 57 18.1 57
Q 8.5 58 18.5 58
R - S 9 60 19.0 60
T1/2 10 62 19.8 62
V 10.5 64 20.4 64

Still unsure?

Our Concierge Service is here to guide you: Whether you need help choosing a design, understanding diamonds, or exploring bespoke options, Bonded Matter is always by your side. Reach out anytime and our team will personally help you find what feels exactly right.

Common questions

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