Most people are often clueless about their own measurements. Going by either UK, US or European sizing is not the best way either as there are many different brands using different measurements. The french goes by 1 2 3. British goes by UK 4 6 8 10 12. US is even worse, Anne Klein sizing is different from BCBG or Kate Spade.
Here's a quick guide on how you can measure yourself:
BUST = B
This is the measurement around the fullest part of your bust or the highest point of your bust. Don't pull the measuring tape too tightly and ensure that you are wearing a bra.
WAIST = W
Measure around the narrowest part of your midsection. Please do not “suck it in”. you will not be doing yourself any favours. Breath normally and relax. Note that where your natural waist sits can be vary for different body shapes, but it is generally above your bellybutton. Sometimes, i use the end of the elbow to gauge.
HIP = H
We are talking about the widest part of your butt. If someone is measuring you, they should be looking at you sideways to find the highest tip of the butt.
SHOULDERS = S
Look straight, feel the rounded edge of your shoulders on one arm. Pull the measuring tape to the other end of your shoulders. This is easier when someone measure you from the back.
LENGTH = L
To get an appropriate or comfortable length for yourself, get someone to do this for you. Look start ahead. Start from the highest point of shoulders (the base of the neck which is also the highest point of your shoulders). Move the measuring tape along till you reach the length you want or are comfortable with.
The length of the sleeves is measured from the tip of the shoulders downwards.