Once you have decided on the type of backpack you want to purchase the next decision is to know what length your backpack should be. This article will cover the main points of how to choose the right size backpack in length, capacity and support.
Measure Up
Before choosing the right length backpack, you will need to perform the following exercise with the help of a friend.
First locate your seventh vertebra; this is the small bony hump at the base of your neck located between your shoulders. Place a piece of tape to mark this point.
Second, locate the point at the small of your back that is level with the top of your hips and mark that point with a piece of tape.
Now get your friend to measure the distance between the two marked points and note the measurement. Your torso will fall into three backpack categories, small (under 18 in/45 cm), medium (18-20 in/45-50 cm) and large (21 in/52 cm upwards).
If your length is just on 18 in/45 cm for example, then choose the medium size pack as this will allow more room for adjustments. With the length of the backpack now sorted, the next consideration is the volume or carrying capacity of the backpack.
Carrying Capacity
This decision is dependent of what type of hiking you will be involved with. A day pack ranges from 945 to 2206 cubic inches or 15 to 35 liters.
A midsize pack range is from 2206 to 4412 cubic inches or 35 to 70 liters and may be used for overnight camping. Finally the expedition backpacks start from 3781 cubic inches or 60 liters and upwards.
The larger expedition backpacks can carry enough gear to allow you to stay on the trail for many days.
Backpack Straps and Belts
Simple shoulder straps will suffice for lighter loads but for heavier loads choose the wider and well padded shoulder straps to prevent discomfort to the shoulder area.
A Chest or Sternum Strap helps to prevent your shoulders from being pulled back and assists with load distribution.
Upper stabilizer straps do just that, stabilize the upper part of the backpack.
The hip belts of a backpack should cup your hips and when they are tightened should not touch or overlap each other.
Shoulder straps should be secured to the backpack just below the 7th vertebra and near the top of the shoulders. They should be comfortable but securely wrapped around the shoulders with the strap padding not being less than 5 inches or 12.5 centimeters below the armpits.
If you are purchasing a small-sized, day backpack they usually do not have a hip belt but as your load capacity requirement increases so does the need for a hip belt. A hip belt assists in load distribution from your shoulders to your hips.
Make sure the padding of the hip belt is soft and of a decent width to provide comfortable support and that it goes full circle under the lumbar pad and is not just attached to the sides of the backpack.