This size chart can help you determine what size to order. Because the different models, it will be easier to order according to your size.
International size chart - American and European measurements
How do I measure my self?
Equipping a flexible measuring tape in centimeters or inches.
Alternatively, but less recommended, use flexible string to measure the body and then stretch it on ruler to convert the string to length in centimeters or inches.
How I measure?
It is important to to carry out the the measurements on exposed body and bare feet.
BUST: Measure the bust at the widest part (under the armpits, usually in nipples height) and around the back. You should also measure the circumference with a bra you used to wear.
WAIST: Measure the waist circumference at the narrowest part of the body (the area above the navel and below the ribs) and around the back. It is also recommended to take an extra measure with adding a finger under the tape measure, especially for pants.
HIPS: pressed your hips together, and measure in fullest part.
RINGS SIZE CHART