Wrap a string around your finger, measure its length with a ruler, and enter the measurement below.
The length of the string wrapped around your finger is equal to the circumference of the circle.
We know that the circumference of a circle is calculated using the formula C = 2 × π × R.
Therefore, once we know the string's length (the circumference),
we can calculate the ring's inner diameter using the formula D = 2 × R = C ÷ π.
There is no exact formula on the internet for converting diameter to ring size,
but I have come up with an approximate formula for this conversion using regression...