There are no standard sizes for clothing, which is why each brand has their own unique cut and fit. Please do not presume you are the same size between brands for a similar product. If you already own a onesie that fits correctly, then use it as a template for these measurements.  

Chest  - Measure the full circumference of your chest just below the armpits
Inside Leg - Measure from the top of your groin down the inside of your leg to the ankle bone. 
Arm LengthMeasure from the end of your shoulder to your wrist
Back Drop - Measure from the back of your neck to under your buttocks

These mid layers will contour to most body shapes when worn thanks to the fabrics in-built stretch. We provide a unisex sizing in these. You should wear them close fitting but not so they are restrictive. Wearing baggy or ill fitting mid layers will lead to the loss of heat and a reduction in their wicking properties.

These mid layers are designed to be worn over the top of our base layers but they can be worn directly next to the skin if required. Sizes for both Sub Zero base layers and mid layers are comparable - so if you wear a Factor 1 plus base layer in large, then you should require a Sub Zero Factor 2 mid layer in the same size and vice versa. However, this may not work out for everybody so please consult the size chart below. 

Please be aware that the inside leg, arm length, and back drop  measurements are taken from the garments unstretched. The chest measurement indicates the range of fit. 

The table below shows the garment measurements for our Factor 2 Onesie and Bib ranges. The bib design is based on the onesie patterns, it just excludes the sleeve length. There is a tolerance of +/- 5mm.

cm in cm in cm in cm in
XSMALL 79-84 31-33 66 26 58 23 78 31
SMALL 86-92 34-36 69 27 60 23.5 81 32
MEDIUM 94-99 37-39 71 28 63 24.5 83 33
LARGE 102-107 40-42 76 30 67 26.5 86 34
XLARGE 109-112 43-44 79 31 69 27 90 35.5
XXLARGE 112-114 44-45 81 32 72 28.5 92 36