Rings
To measure the ring size using a ring that fits, you need measure the internal diameter of the ring. Write down this measurement in millimeters, and use the conversion chart below to find your ring size. If you don't have a ring to use, follow these easy steps:

Inside Circum. (IN)	Inside Circum. (MM)	US/CA	UK/IE/AU	DE
1.84	46.8	4	H	15
1.87	47.4	4.25	H-1/2	15.25
1.89	48	4.5	I	15.5
1.92	48.7	4.75	J	---
1.94	49.3	5	J-1/2	15.75
1.97	50	5.25	K	16
1.99	50.6	5.5	K-1/2	16.25
2.02	51.2	5.75	L	---
2.04	51.9	6	L-1/2	16.5
2.07	52.5	6.25	M	16.75
2.09	53.1	6.5	M-1/2	17
2.12	53.8	6.75	N	---
2.14	54.4	7	N-1/2	17.25
2.17	55	7.25	O	17.5
2.19	55.7	7.5	O-1/2	17.75
2.22	56.3	7.75	P	---
2.24	57	8	P-1/2	18
2.27	57.6	8.25	Q	18.25
2.29	58.2	8.5	Q-1/2	18.5
2.32	58.9	8.75	R	18.75
2.34	59.5	9	R-1/2	19
2.37	60.1	9.25	S	19.25
2.39	60.8	9.5	S-1/2	19.5
2.42	61.4	9.75	T	19.75
2.44	62.1	10	T-1/2	20
2.47	62.7	10.25	U	20.25
2.49	63.3	10.5	U-1/2	20.5
2.52	64	10.75	V	---
2.54	64.6	11	V-1/2	20.75
2.57	65.2	11.25	W	---
2.59	65.9	11.5	W-1/2	21
2.62	66.5	11.75	X	---
2.65	67.2	12	X-1/2	21.25
2.67	67.8	12.25	Y-1/2	21.5
2.7	68.4	12.5	Z	21.75
2.72	69.1	12.75	Z-1/2	---
2.75	69.7	13	Z+1

Necklace
First, you need to understand the exact look you are going for with your necklace using the chart of standard necklace lengths.
Standard necklace lengths:
There are roughly 4 standard looks are that are based on variants of necklace lengths, the most common are choker and princess lengths.

Length - Inches	Length - CM	Style	Worn best with
17"	43cm	Choker	Almost everything
18"	46cm	Princess	Almost everything
20"	51cm	Matinee	Great for both business and casual wear
22"	56cm	Opera	High necklines and evening wear

Bracelets
Step 1: Get your wrist measurement
1. Measure your wrist. Using a measuring tape, measure tightly just above the wrist bone as below.
If you do not have a measuring tape, you can use a thin strip of paper. It is important to use a thin, flat paper strip. If you use a thick string, you will end up with a measurement 0.5 - 1 cm longer than your actual wrist size.

2.Round up the measurement. Take the measurement from either the measuring tape or paper strip and round it up. This shall be your wrist size.

Step 2: Convert your wrist measurement into bracelet size. You can convert it using the size guide for that particular design with a wrist size column.

Bracelet Sizing
Inches	CM
6	15.2
7	17.8
8	20.3
9	22.9

Based on this size chart, if your wrist size as measured from step 1 is 7 Inches, your size should be 17.75 cm for this style.