How to measure your chest
We recommend using a cloth tape measure for taking your measurements.
If that`s not possible you could try using a piece of string, mark it and measure that with what ever solid measure you have to hand.
Take your time, remember to take a deep breath while doing it (this will help allow for a back protector if applicable), and double check again.
It is also very important to remember, where applicable, all sizes given include the liner being in. Some jackets have removable liners. If you plan to ride with the liner out you should take that into consideration and adjust your measurements accordingly.
Measure from upper/top of armpit across the chest to the upper/top of the other armpit, then across back to the first armpit.
Take several measurements. The largest measurement is the one you want to use.