1) Measure your torso circumference just below your chest muscles. This can be done with a fabric tape measure or a piece of string and metal tape measure.
|NuMetrex™ Cardio Shirt Sizing Chart|
|rib cage below pecs (in)||36-38||38-41||41-44|
2) If this is not practical, use the following chart, and if your height and weight fall on a sizing border, we would recommend going to the smaller size for maximum performance.