How to Measure Yourself for a Trail Running Vest
A trail vest that's even one size off doesn't just feel wrong, it bounces, chafes and stops doing its job. Getting it right takes two minutes with a tape measure, done before you order rather than after.
The two measurements that matter
Measure around the base of your ribcage, just under your chest, keeping the tape level. Then measure around the widest part of your chest, once while breathing in and once while breathing out, and use the larger number. Those two figures, not your jacket size or a guess, are what a size chart is actually built on.
Snug is correct, tight is not
A trail vest is meant to sit close to the body so it doesn't move when you run, which feels different from a jacket or backpack you're used to. You should be able to slide a finger between the vest and your body without much effort, and still take a full breath with the sternum straps closed. If you can't, size up.
Try it loaded, not empty
An empty vest almost always feels fine. Fill it the way you actually would, soft flasks in the front pockets, a light layer in the back, and see how the fit holds once there's real weight in it. Fit can change noticeably between empty and loaded, especially around the shoulders and ribcage.
LECAMO sizing across the range
All three LECAMO packs, the ROOT5, ROOT8 and ROOT18, run S to XL using the same close-to-body fit philosophy, so if you've measured once for one size, you're set across the range. Check the size guide on each product page against your own numbers rather than sizing based on a previous brand, since fit systems vary a lot between manufacturers.