How to Fit a Backpack (Most People Get It Wrong)

A pack that fits carries 40 pounds better than a lighter pack that does not. Fit is free performance, and almost everyone leaves some on the table.

Measure your torso

From the C7 vertebra — the bump at the base of your neck when you tip your head forward — to the top of your iliac crest, the shelf of your hips. That number, not your height or shirt size, picks the frame size.

Load it before you judge it

Twenty-five pounds minimum. An empty pack tells you nothing; the suspension only reveals itself under load.

Tension in order

1. Hipbelt — centered on the iliac crest, snug, carrying 70–80% of the weight.
2. Shoulder straps — pull down and back until they contact without lifting the hipbelt.
3. Load lifters — 45 degrees off the shoulder, tensioned lightly. They are not carry straps.
4. Sternum strap — last, loose enough to breathe.

The check

Walk stairs for five minutes. If your shoulders take the load, the hipbelt is too low or too loose. If the pack sways, the stabilizers need tension. Adjust one thing at a time.