Find Your Torso Length

Just because you are a certain height — say a 5'9" female or 6' male — does not mean you automatically need a "large" or "tall" pack. Your torso length, not your height, determines your pack size. Here's how to measure yours:

• Have a friend locate the bony bump at the base of your neck, where the slope of your shoulder meets your neck. This is your 7th cervical (or C7) vertebra. Tilt your head forward to locate it more easily.
• Using a flexible tape measure, your friend should start at that spot and measure downward along your spine.
• Place your hands on your hips so you can feel your iliac crest, which serves as the "shelf" of your pelvic girdle. (It's the first hard thing you feel when you run your fingers down from the sides of your ribcage.) Position your hands so your thumbs are reaching behind you.
• Have your friend finish measuring at the point where the tape crosses an imaginary line drawn between your thumbs. This distance is your torso length.

Use your torso length measurement to find your best pack size. Generally, manufacturers size their pack frames something like this:

• Extra Small: Fits torsos up to 15 ½"
• Small: Fits torsos 16" to 17½"
• Medium/Regular: Fits torsos 18" to 19½"
• Large/Tall: Fits torsos 20" and up

Determine Your Hip Size

While not as crucial as your torso length, your hip measurement is useful to know. It's especially helpful if you are considering a pack that offers interchangeable hipbelts.

Take your tape measure and wrap it around the top of your hips, the "latitude line" where you can feel your iliac crest — those two pointy bones just above the front pockets on your pants. A properly positioned hipbelt will straddle your iliac crest, about an inch above and below that line.