Your Pack Is Your Most Important Piece of Gear
Everything else you own goes inside it or hangs off it. A poorly fitted, wrongly sized, or badly designed backpack will cause pain, inefficiency, and genuine misery on a multi-day expedition. Spend time getting this decision right — it's worth far more effort than agonising over sleeping bag fill power or tent pole materials.
Step 1: Decide on Capacity (Litres)
Pack capacity is measured in litres and is the first filter you should apply. General guidance:
| Trip Length | Recommended Capacity |
|---|---|
| Day hike | 10–25 L |
| Overnight (1–2 nights) | 25–40 L |
| Weekend (2–4 nights) | 40–55 L |
| Extended expedition (5+ nights) | 55–80+ L |
Resist the temptation to always go bigger. A larger pack invites overpacking, which leads to a heavier load and more fatigue. Ultralight trekkers regularly complete week-long routes with 40–45 L packs.
Step 2: Understand Frame Types
Internal Frame Packs
The dominant design for modern backpacking. The frame (usually aluminium stays or a semi-rigid back panel) sits close to your body, keeping the centre of gravity high and improving balance on technical terrain. Ideal for off-trail hiking and scrambling.
External Frame Packs
The older design, still popular for heavy load-carrying on established trails. The rigid external frame keeps the load off your back and improves ventilation but performs poorly on technical terrain. Common for bushcraft and expedition resupply.
Frameless Packs
Favoured by ultralight backpackers. No frame means lighter weight, but load-carrying comfort drops significantly above around 10–12 kg. Requires careful packing technique (soft items act as the "frame").
Step 3: Get the Fit Right
This is the most critical factor and the one most often skipped when buying online. A pack fits when:
- The hip belt sits centred on your iliac crest (the top of your hip bones), carrying 70–80% of the pack's weight
- The shoulder straps curve around your shoulders without gaps and aren't bearing the majority of the weight
- The load lifter straps angle upward at roughly 45 degrees from shoulder to pack
- The sternum strap sits about 2–3 cm below your collarbone
Torso length — not height — determines pack size. Measure from the C7 vertebra (the bony bump at the base of your neck) to the top of your hip bones. Most manufacturers offer Small, Medium, and Large torso fits accordingly.
Step 4: Evaluate Key Features
Access Points
Top-loading packs are simple and durable. Panel-loading packs (with a zip along the back face) allow easy access to items deeper in the pack. Some packs offer both. For expedition travel, top-loading is generally more rugged.
Hip Belt Pockets
Invaluable for trail snacks, sunscreen, phone, and map access without removing the pack. Make sure they're large enough to be useful — some are token-sized.
Hydration Compatibility
Most packs now include a sleeve and port for a hydration reservoir (bladder). Useful on long waterless stretches, though some trekkers prefer bottles for simplicity and easier monitoring of intake.
Rain Cover
Check whether a rain cover is included or sold separately. Some packs use a roll-top dry-bag style design instead. Either way, for wet environments, line your pack with a bin liner as an additional waterproofing layer — covers tend to fail in sustained downpours.
Weight Considerations
Pack weight (empty) matters. A heavy pack before you add gear compounds over distance. As a rough benchmark, aim for an empty pack weight no more than 10% of your loaded total. If you're targeting ultralight setups, look for packs under 1 kg empty.
Try Before You Buy — If You Can
Visit a specialist outdoor retailer and ask to be fitted properly. Load the pack with weight (good stores have sandbags for this) and walk around. No amount of online research replaces 10 minutes with a loaded pack on your back. Your spine will thank you.