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Pack fit

Two people of the same height can need different pack sizes. What decides it is torso length, and you can measure it at home in two minutes.

C7the bump at thebase of the neck Iliac cresttop of the hip bones Torsolength

Find your torso length

You'll need a soft tape measure and someone to hold it.

  1. Find C7Tip your chin to your chest. The bony bump that sticks out most at the base of your neck is the C7 vertebra. Then stand up straight again.
  2. Find the top of your hipsPut your hands on your hips, thumbs pointing back, and slide them up until you feel the top edge of the hip bones (the iliac crest).
  3. Measure between themHave your helper run the tape down your spine from C7 to the imaginary line between your thumbs. That number is your torso length.
18.0 in

Size ranges are Osprey's published torso ranges, shown as an example of how one brand sizes packs; every brand sets its own. Osprey size guide

The other measurement

Measure at the hip bones

Hipbelt size is measured around your hips at the iliac crest, the same spot as before, not at your trouser waist. Most hipbelts adjust across a wide range, roughly mid-20s to mid-40s of inches.

Why it matters

On a loaded backpacking pack, most of the weight, 80% or more by REI's guidance, should ride on your hips rather than your shoulders. On a daypack, a hipbelt starts to pay off once the load goes past about 15 lb.

Sources: Osprey, Size & Fit; REI, How to Choose a Backpack; REI, Daypacks.

Adjust in this order

Put 10 to 20 lb in the pack first. An empty pack never feels like a loaded one.

  1. Loosen every strap: hipbelt, shoulder straps and load lifters.
  2. Put it on and center the hipbelt over your hip bones, padding half above and half below.
  3. Buckle and tighten the hipbelt so it wraps your hips.
  4. Pull the shoulder straps down and back until they're snug, not tight.
  5. Snug the load lifters. On a pack that fits, they angle back at roughly 30 to 60 degrees.
  6. Check where the shoulder straps meet: about 1 to 2 in below C7. Much more or less means another size.
  7. Look for gaps between the straps and the tops of your shoulders. A gap usually means the pack is too long for you.
  8. Clip the sternum strap about 2 in below your collarbones.

Adapted from Osprey's pack-fitting instructions and REI.