How to Find Your Perfect Ring Size
Cian Griffin 4 min read

How to Find Your Perfect Ring Size

A beautiful ring is more than just an accessory—it’s a symbol, a memory, and a piece of craftsmanship designed to last a lifetime. But even the most exquisite design can’t shine if it doesn’t fit perfectly.

At Griffin and Co Fine Jewellery, we know that finding the right size can feel like a daunting task, especially when shopping online or planning a surprise. To help you shop with confidence, we’ve put together this essential guide to measuring your ring size at home.

Why Getting the Right Fit Matters

A well-fitting ring should slide over your knuckle with a small amount of resistance and sit snugly at the base of your finger.

  • Too Loose: You risk the ring spinning or, worse, slipping off entirely.

  • Too Tight: It can become uncomfortable during warm weather or after a long day when fingers naturally swell.

Method 1: The "Existing Ring" Test (Most Accurate)

If you already own a ring that fits the intended finger perfectly, this is the safest method.

  1. Select a ring that fits the exact finger you are buying for.

  2. Place the ring on a flat surface.

  3. Use a ruler to measure the inside diameter in millimeters (mm). Note: Do not include the metal band itself in the measurement.

  4. Compare your measurement to our Conversion Chart below.

Method 2: The Paper or String Method

No ring? No problem.

  1. Cut a thin strip of paper or a piece of non-stretchy string.

  2. Wrap it around the base of your finger where the ring will sit.

  3. Mark the point where the ends overlap with a pen.

  4. Measure the length (circumference) against a ruler in mm.

Expert Tips for Accurate Results

  • Timing is Everything: Fingers are smallest in the morning and when you're cold. For the best result, measure at the end of the day when your hands are warm.

  • Consider the Knuckle: If your knuckle is significantly wider than the base of your finger, take two measurements and choose a size in between.

  • Dominant Hand vs. Non-Dominant: Your dominant hand is often slightly larger—always measure the specific finger you plan to wear the ring on!

  • Wide Bands: If you are eyeing a "chunky" or wide-band design, we recommend choosing one size larger than your standard fit for comfort.

International Ring Size Conversion Chart (A-Z)

UK Size US Size EU Size Diameter (mm)
A 0.5 37.8 12.04
B 1 39.1 12.45
C 1.5 40.4 12.85
D 2 41.7 13.26
E 2.5 42.9 13.67
F 3 44.2 14.07
G 3.5 45.5 14.48
H 4 46.8 14.88
I 4.5 48.0 15.29
J 5 49.3 15.70
K 5.5 50.6 16.10
L 6 51.9 16.51
M 6.5 53.1 16.92
N 7 54.4 17.32
O 7.5 55.7 17.73
P 8 57.0 18.14
Q 8.5 58.3 18.54
R 9 59.5 18.95
S 9.5 60.8 19.35
T 10 62.1 19.76
U 10.5 63.4 20.17
V 11 64.6 20.57
W 11.5 65.9 20.98
X 12 67.2 21.39
Y 12.5 68.5 21.79
Z 13 69.7 22.20

Buying a Gift? How to Measure discreetly

Buying for someone else? Here are three ways to get it right "unnoticed":

  1. The Stealth Borrow: Borrow a ring from their jewellery box (ensure it's for the correct finger!) and use the "Existing Ring" method.

  2. The "Best Friend" Intel: Friends often know these details—or can find out much more naturally than you can!

  3. The Average Guess: If you're truly stuck, the most common ring size for women is M to N, and for men, it is T to U.

Still Unsure?

Sizing is an art, and we are here to help. If you need a custom size or a professional consultation, the expert jewellers at Griffin and Co Fine Jewellery are just a message away.

Click here to contact our expert team for bespoke sizing advice

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