How to take body measurements

The most important measurement for tops is the chest circumference, 
and for pants it is the hip circumference.
Both measurements should be taken parallel to the floor
and at their widest circumference around the body.
Outer leg and inner leg length are measured to the floor.

The shoulder with is taken between the acromion bones.

The upper arm circumference is measured at the fullest part of the upper arm. 

The arm length is measured with the elbow slightly bent,
starting from the acromion bone, over the elbow, to the wrist bone.