Why Your Torso Length Matters
Finding the right backpack size starts with one key measurement: your torso length. Unlike clothing sizes, backpack fit is based on the length of your back — not your height. Two people of the same height can need completely different pack sizes depending on their body proportions.
In this guide, we’ll show you how to measure your torso length at home using a simple tape measure. With this quick measurement, you’ll be able to choose the correct Gregory pack size and enjoy better comfort, balance, and performance on the trail.
Step‑by‑Step: How to Measure Your Torso Length
1. What is a torso length?
A torso length (also known as back length) is the distance from your C7 vertebra (the bony point at the base of your neck) to your iliac crest (the top of your hip bones). This measurement represents the length of your upper body and is used to determine the correct backpack size.
2. How to locate your measuring points
Top point: C7 vertebra
Gently tilt your head forward. You will feel a small, prominent bump at the junction of your neck and shoulders, that’s your C7 vertebra, and it’s the reference point for all torso measurements.
Bottom point: Iliac crest
Place your hands on your hips with thumbs pointing backward and index fingers forward. Slide your hands up until you reach the top ridge of the hip bone, the point where your fingers naturally level out marks the iliac crest, the lower measurement point along your spine.
3. Position the measuring tape
With the upper point located, place the end of a soft measuring tape directly on your C7 vertebra.
Let the remaining length of the tape fall down your back toward your hips.
Using your free hand, return to the position where your thumb rests on the top of your hip bone. This helps you see exactly where the measuring tape intersects with the level of your iliac crest.
4. Locate and mark your torso length
With one hand, keep the tape in place at your neck.
With your other hand, return to the top of your hip bone (iliac crest) and slide your thumb horizontally toward the center of your lower back.
When your thumb reaches the point where the tape crosses the height of your hip bone, hold that exact spot on the tape using your thumb or index finger.
This is your torso length measurement point.
5. Finalize the measurement
Release the top end of the tape near your neck, but keep holding the marked point at your lower back so the position does not shift.
6. Read your torso length
Bring the tape around to your front while holding the marked spot.
The number directly above your thumb (the marked point) is your torso/back length.
Choose your pack
Once you know your torso length, you can find out which size you should buy in whichever Gregory pack you like.
And remember, all Gregory packs are sized the same regardless of gender, so a medium is a medium whether it’s unisex, a men’s pack, or a women’s pack.
Try on the pack
We always recommend throwing at least 4,5 - 9,0 kg in the pack. From there, the most important thing you can do is make sure the top edge of hipbelt is sitting 2.5 cm above your iliac crest shelf.
Next, the shoulder straps should wrap smoothly over your shoulders and should start wrapping onto your back, about 8 cm below the top of your shoulders. If your shoulder strap starts lower than 8 cm, try a larger size.
To make sure your pack is adjusted correctly, follow our guide on how to fit a backpack.