The goal of lightweight backpacking is to reduce the amount of gear weight you carry on backpacking trips without compromising on comfort and safety. The best way to approach this is to weigh your existing gear on a postal or kitchen scale to determine the heaviest items on your backpacking gear list. While every ounce or gram matters, you can usually get the greatest gear list weight reductions by focusing on the four heaviest items in your gear list, called the Big 4.
If you sleep in a tent or on the ground under a tarp, your Big 4 will probably include:
- Tent or Tarp
- Sleeping Bag/Quilt
- Sleeping Pad
If you use a hammock, your Big 4 will probably include:
- Shelter (tarp and hammock)
- Top quilt
- Underquilt or foam pad
Two Gear Weight Reduction Approaches
There are two approaches to reducing the weights of your big 4 gear items.
Buy It Down
The first is to replace them with lighter-weight alternatives if and when you can afford to do so. In other words, buy it down. There are plenty of options these days to buy lighter weight gear new or used and to sell your existing gear to help bankroll it.
Narrow Your Objectives
The second, which requires more trip planning, is to narrow your objectives by reducing the temperature range and weather conditions that you intend to backpack in, so you bring lighter weight gear that’s not as general-purpose as what you may have carried before. For example, if you only intend to backpack in summer, you can often reduce the temperature rating of your sleep insulation and significantly reduce the weight of your gear. Lighter weight sleep insulation is usually smaller in volume, letting you use a smaller and lighter-weight backpack, carry lighter weight clothing, go stoveless, and so on.
There’s a big difference between sleeping in 20 degrees and sleeping in 40 or 50 degrees, that you can exploit to reduce your gear weight. This approach is often less expensive than the outright replacement of more general-purpose gear intended for a wider range of conditions.
Big 4 vs Big 3
The Big 4 and the Big 3 are used interchangeably by educators to explain how to reduce the weight of backpacking gear lists, although the Big 4 is the more recent adaption of the concept. The Big 3 included a backpack, shelter, and sleep system (sleeping bag and sleeping pad) as a single unit.
Many people had a hard time comprehending what a sleep system was, so the big3 became the Big 4 and now includes a backpack, shelter, sleeping bag/quilt, and sleeping pad if you sleep on the ground; and if you sleep in a hammock the Big 4 includes a backpack, shelter (including hammock and tarp), top quilt, and underquilt/sleeping pad.