Ring Size
Calculate Ring Size instantly with the exact formula and a worked example.
Ring Size
Ring inner diametermm
Circumference (EU size)
54.3496mm
RU size
17.5
EU size
54
US size
7
UK size
N½
JP size
14
More about: Ring Size
What it calculates
The “Ring Size” calculator computes Circumference (EU size) in mm from 1 parameter: ring inner diameter (mm).
A converter between units of measure, currencies, and sizes.
Example calculation
With parameters Ring inner diameter = 17.3 mm the result is 54.35 mm.
How to use
- Enter ring inner diameter — each field above is adjustable with a slider.
- Circumference (EU size) (mm) is calculated automatically as you type.
- Check the worked example below to see the formula applied to real numbers.
- Copy the result or bookmark this calculator.
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FAQ
How is Ring Size calculated?
The Ring Size calculator computes Circumference (EU size) (in mm) from ring inner diameter. Enter your values above and the exact formula is applied instantly; a worked example with real numbers is shown below.
Is the Ring Size calculator free?
Yes. It is completely free, needs no signup, runs entirely in your browser, and sends no data to any server.
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