Suit sizing chart    
size 44 46 48 50 52 54 56 58 60 62
height 66-67" 67-68" 68-69" 69-71" 71-72" 72-73" 73-74" 74-75" 75-76" 76-77"
weight 111-120 120-133 133-146 146-160 160-174 174-187 187-200 200-213 213-226 226-244

How to read this chart:
If you are 72" and weigh 146 lbs. = size 52 (height number is larger than the weight).
If you are 72" and weigh 200 lbs. = size 56* (weight number is larger than your height).
*Now if the suit is too long, we could always send you extra Nomex thread so you can cut and hem your suit.

Info:
Most burns occur not from direct contact with flame, but from the heat. Because of this the space between the layers of a suit protect you just as much as the fabric does. This space acts as a cushion of cool air between your skin and the heat from the flame. It takes about six seconds for the temperature of a flame to transfer through a one-layer suit. A two-layer suit gives you about 14 seconds. A three-layer suit uses two cushions of air between three layers of fabric for 18-26 seconds of protection from the heat.
(All OMP driving suits are 3-layers of Nomex).