How to Choose a Backpacking Backpack for Travel? | Fit First, Liters Second

A travel backpack should be chosen by torso length, hip circumference, and trip length, not by your height or a brand’s size label.

Get the torso measurement wrong by two inches and a pack that looks perfect on the rack will dig into your shoulders by day three. The fit rules below come from Osprey’s sizing guidance and REI’s fit and torso guide, and they take about five minutes and a soft tape measure to apply.

Why Torso Length Decides The Size

Pack size is set by torso length—not overall height, weight, or shoulder width—because the frame has to span from your hip bones to the base of your neck, and that span varies wildly between people of the same height. Osprey states plainly that pack size is based on torso length rather than height or weight, with different size ranges across models.

Measure it in three steps:

1. Find the C7 vertebra—the bony bump at the base of your neck that stays put when you tilt your head forward.
2. Find the iliac crest, the top of your hip bone on either side.
3. Run the tape along your spine between those two points and write down the number in inches.

Have someone help with step three. A self-measured torso length read by feel is usually off by an inch or more, and an inch is the difference between a size S and a size M in most pack lines.

How To Adjust A Loaded Pack So The Weight Sits On Your Hips

Load the pack with about 25 to 30 pounds, put on the hipbelt first so it rests on top of your hip bones, snug the shoulder straps last, and finish with the load-lifters and sternum strap. Most of the weight should land on your hips, not your shoulders—that transfer is the entire reason a framed pack carries better than a duffel.

The load-lifter straps that run from the top of the shoulder straps to the pack should sit at roughly a 30 to 60 degree angle, the range Osprey’s fit guidance describes as ideal for pulling weight forward onto the hips. If the straps run nearly horizontal, the load is hanging off your shoulders instead.

Two fit checks matter more than any capacity rating. A pack can have exactly the volume you need and still carry badly if the torso length is off or the hipbelt doesn’t wrap your hip bones—torso and hip fit must both work before load transfer happens at all. Beyond that, sizing and available size ranges vary by model, including men’s and women’s versions and travel-specific builds.

Travel Packs Vs Trekking Packs: What Changes

Travel packs trade tunable fit for convenience, while trekking packs tune fit but carry worse on a plane. Osprey’s luggage guide notes that a backpack or small carry-on around 20–22 inches tall offers plenty of space while keeping you mobile, and the same guidance identifies the Farpoint 40 and Farpoint 55 as travel models built around a fixed harness for airplane use. Trekking packs commonly use adjustable harness systems instead, which let you dial in torso length but add bulk and hardware you rarely need in an airport.

Four mistakes account for most bad pack purchases: choosing by height instead of torso length, ignoring hipbelt fit and carrying weight on the shoulders, mismatching capacity to trip duration, and assuming one size fits all. Osprey’s guidance is explicit that sizing depends on torso length and the specific pack model, so a size M in one line is not a size M in another.

If you’d rather start from a shortlist than measure forty packs, our tested roundup of the best backpacking travel backpacks for carry-on trips pairs each pick with the torso range it actually fits.

Frequently Asked Questions

Can I size a pack by my height alone?

No. Height tells you almost nothing about which pack frame will fit, because two people the same height can differ by several inches in torso length. Measure from the C7 vertebra at the base of your neck to your iliac crest along the spine, then match that number to the model’s size chart.

How much weight should rest on my shoulders?

Very little. In a well-adjusted pack, the hipbelt carries most of the load and the shoulder straps mostly keep the pack against your back. If your shoulders ache within an hour, loosen the shoulder straps, tighten the hipbelt, and check that the load-lifters sit at roughly a 30 to 60 degree angle.

Is a fixed harness bad for travel?

Not if the torso sizing is right. Travel packs like the Farpoint 40 and 55 use fixed harnesses to cut weight and simplify the bag for flights, which works well when you buy the correct torso size. Adjustable harnesses matter more for trekking, where pack weight and fit change trip to trip.