Ring Sizer

Measure at home in seconds — no sizer kit required.

Measure an existing ring

Place a ring that fits well on a ruler and measure the inner diameter in millimetres. Calibrate your screen first for true 1:1 scale.

Step 1 — Calibrate your screen
Credit card
Hold a credit card against the bar Drag until the bar exactly matches your card width (85.6mm).
96 PPI
Adjust slider until bar matches your card.
Step 2 — Set the diameter
Inner diameter 16.5 mm
13 mm (size 3)25 mm (size 15)
Circle drawn at true 1:1 scale — place your ring on screen to compare
US / CA
5½
UK / AU
K½
EU / FR
52
Japan
11
Diameter
16.5mm
Tip: After calibrating, hold your ring directly against the screen and match the inner hole to the circle.

Measure your finger

Use a strip of paper or string to measure the circumference of your finger.

1
Wrap

Wrap a thin strip of paper snugly around the base of your finger.

2
Mark

Mark where the paper overlaps, then measure the length with a ruler.

3
Enter below

Type the measurement and get your size instantly.

International ring size chart

Full reference guide across all major sizing standards.

Diameter (mm)US / CAUK / AUEU / FRJapanCircumference (mm)