Cutting base weight without cutting what keeps you warm

A lighter pack makes a long day kinder, on your knees and your shoulders. But the goal is a pack that is light enough, not a pack that is as light as possible. The grams that keep you warm, dry and found are the last ones to go.

This is how we approach it, with numbers from our own checklist.

Start by knowing what you carry

Base weight is the weight of everything in your pack that does not get used up. Food, water and gas are left out, because they change from day to day.

Before you change anything, weigh what you have. Kitchen scales are fine. Write each item down with its weight, or build a list on our checklist and tick what you own: the base weight still counts ticked items, because you still carry them. For a two-night autumn trip, our starting list comes to around 6.6 kg. A winter overnight comes to around 10 kg, and that difference is mostly warmth you need.

Seeing the numbers in one place does most of the work.

The big three

Most of your base weight sits in three items: the shelter, the sleeping bag and the pack. On our autumn list, the tent, bag and pack together make up more than half of it. That is where cuts make the biggest difference, and also where a bad cut costs the most.

Shelter. The Ridgeline 2 is 1,180 g. The Fernlight 1 tarp-tent is 780 g, because it uses a trekking pole instead of a tent pole and has a single wall. That is 400 g saved, in exchange for one person's worth of space and more condensation on still, damp nights. For a solo walker from spring to autumn it is a good trade. For two people, or in winter, it is not.

Sleeping bag. Down gives more warmth for its weight than synthetic fill. The Ember 0 is 1,050 g; the Hollow 0, with the same comfort rating, is 1,480 g. That 430 g is real, but it is a trade, not a free saving: the down bag costs more and needs keeping dry. What you should not do is swap to a lighter bag with a warmer comfort rating than the nights you expect. That is the one cut that turns a trip into a long night.

Pack. A lighter load fits in a smaller pack, and a smaller pack weighs less. The Highfold 45 is 1,150 g; the 65 is 1,780 g. Cut the other items first, then see whether your kit fits in the smaller pack, not the other way round.

The middle: smaller wins that add up

Once the big three are settled, look down the list for items that are heavier than they need to be, or that you carry twice.

• Poles. Carbon poles at 380 g the pair against aluminium at 520 g saves 140 g. They are stiffer and can snap under a sideways load where aluminium would bend, so it is a choice, not a fix.
• Cooking. One person rarely needs more than a 750 ml pot. If you carry a mug as well, check that you actually use both.
• Water. Soft bottles weigh 36 g each against 170 g for a hard bottle. From spring to autumn, the soft ones do the job. Carry the water you need to reach the next good source, not the whole day's supply, and use a filter to refill.
• Duplicates. Two knives, two lighters, three stuff sacks for the same clothes, a spare fleece and a spare jacket. Pick one of each and put the rest back.
• Packaging. Take food out of boxes and decant sun cream into a small tube.
• Things that do two jobs. A foam mat is also a sit mat and a stove platform. Trekking poles hold up a tarp-tent. A pot can be a mug.

None of these saves much alone. Together they often come to several hundred grams, and none of them makes you colder.

What we do not cut

Some items are light already, and the risk of leaving them behind is far greater than the saving. We carry these on every trip, whatever the pack weighs.

• Insulation you can wear. A warm layer you can put on when you stop, and sleep in if the night is colder than you planned.
• A waterproof jacket. Wet and wind together are what make walkers cold.
• A sleeping bag and mat for the coldest night you expect, chosen by the comfort rating and R-value, with margin.
• A headlamp, even on a day hike.
• Map, compass and the skill to use them, as well as a phone.
• A first-aid kit, a whistle and an emergency bivvy bag. Together they weigh under 400 g.
• A way to treat water, with a backup.
• Enough food, with a little spare.

In winter, add the extras the season asks for: the warmer bag and mat, gloves with liners, a warm hat, a flask and microspikes for icy paths. A light winter pack is still heavier than a summer one, and that is as it should be.

Weight and skill go together

The lightest set-ups work because the person carrying them has the experience to use them well. Cut weight a step at a time, try each change on a short trip close to home, and keep the margin where it matters.

The checklist is a starting point. Use it to see your numbers, swap where it makes sense for you, and check the forecast and your route before you go.