Ultralight backpacking

Ultralight backpacking (sometimes written as UL backpacking) is a style of lightweight backpacking that emphasizes carrying the lightest and least amount of gear.^[1] While no technical standards exist, some hikers consider "ultralight" to mean an initial base weight of less than 4.5 kg (9.9 lb).^[2] Base weight is the weight of a fully loaded backpack at the start of a trip, excluding worn weight and consumables such as food, water, and fuel (which vary depending on the duration and style of trip). Base weight can be lowered by reducing the weight of individual items of gear, or by choosing not to carry that gear. Ultralight backpacking is most popular among thru-hikers.

In the United States, the terms "light" and "ultralight" often refer to backpackers who carry gear with a base weight below 6.8 and 4.5 kg (15 and 10 lb) respectively. These weights are more easily achievable for smaller hikers. Larger hikers may need to carry clothes, shelters, sleep systems and backpacks that weigh up to 50% more. In contrast, traditional backpackers have base weights of 6.8 to 13.6 kg (15 to 30 lb), and in some cases (usually winter trips, extended trips in varying conditions, and multi-purpose trips requiring additional gear such as photography, fishing, and climbing) as much as 25 kg (55 lb) or more.