Ultralight hikers obsess over grams, but how you pack those grams matters just as much as how many there are. A well-packed 20-pound load can feel lighter than a badly packed 15-pound load, because weight distribution decides how much strain lands on your shoulders, hips, and knees. The principles are simple — heavy items close to your back, weight centred at the right height, and everything you need during the day within easy reach — but they are easy to get wrong when you are rushing out of camp in the morning.

Pack in three zones. The bottom zone holds light, bulky items you will not need until camp: your sleeping bag, sleep clothes, and sleeping pad. The middle zone, closest to your back, holds your heaviest items — food, water, and your cook kit — because weight carried near your spine and at mid-back height is the most stable and easiest to carry. The top zone holds items you need during the day: your rain jacket, first aid kit, lunch, and navigation tools. This system keeps your centre of gravity high enough for good balance on uneven ground but low enough that the pack does not pull you backwards on steep climbs.

The single most important packing rule is that dense, heavy things belong against your back, not at the front of the pack. A food bag or water bladder hanging at the back of the pack creates a lever that pulls you backwards and forces your shoulders and lower back to compensate all day. Push your food bag and stove into the middle of the pack, right behind the back panel, and fill the gaps around them with soft items like clothing. If your pack has a hydration sleeve, use it — it is designed to hold water in exactly the right place. Never strap heavy items to the outside of the pack if you can avoid it, because swinging weight destroys your balance on rocky trails.

Your hip-belt pockets, shoulder-strap pockets, and lid or brain pocket are for things you need without taking the pack off: snacks, sunscreen, lip balm, a map or phone, and your water filter. Keep your rain jacket in an outside pocket or at the very top of the main compartment so you can reach it in seconds when the weather turns. Your first aid kit and repair kit should be easy to reach too, because you never want to unpack a full bag to find tape for a blister. A small dry bag for electronics and a map case keep the essentials dry even if the pack gets soaked. Everything else can stay buried until camp.

Use compression straps to pull the load tight against the pack and stop it shifting as you walk — a load that swings with every step wastes energy and strains your knees. Balance the pack side to side: a water bottle on one side only will pull you off-centre over a long day, so carry bottles in pairs or use a bladder. Repack slightly each morning as food gets eaten and water levels change; a pack that was perfectly balanced on day one will be top-heavy or lopsided by day three if you never adjust it. Take thirty seconds at each water stop to tighten straps and shift anything that has settled — your knees will thank you at the end of the day.

The most common mistake is packing by category instead of by weight and access — putting all the cooking gear together at the top, for example, because it feels tidy. Another is overstuffing: a pack filled beyond its capacity rides badly no matter how you arrange it, so if you have to force the lid closed, you are carrying too much. Strapping a sleeping pad or tent to the outside is sometimes unavoidable, but keep it centred and tight so it does not swing. Finally, do a test pack at home before every trip and walk around the block with the full load — ten minutes of checking at home beats ten miles of regret on the trail.