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Trail terms

Ultralight

Also called UL

What is ultralight backpacking?

Ultralight is a style of backpacking built around a base weight under 10 lb. It gets there by making the big three lighter and by carrying fewer things, which trades comfort in camp and margin in bad conditions for comfort while walking.

Ultralight at a glance

Ultralight
Base weight under 10 lb
The big three
Pack, shelter, sleep system
Trades away
Durability, camp comfort, margin

Where the line is drawn

The commonly used line is a base weight under 10 lb, with lightweight sitting under 20 and superultralight under 5. The numbers are conventions rather than rules, and the underlying idea is more useful than the threshold: carrying less makes you faster, less tired at the end of a day, and less likely to be injured by the load itself.

The big three

Nearly all of the weight lives in three items. Pack, shelter and sleep system make up the bulk of a base weight, and going from a 5 lb pack, a 5 lb tent and a 4 lb bag to a 2 lb pack, a 2 lb trekking-pole shelter and a 1.5 lb quilt is most of a 10 lb saving before you've touched anything else. The rest is a long tail of small decisions and diminishing returns.

What it costs you

What it costs is real and worth being honest about. Ultralight gear is generally less durable, less comfortable in camp, and less forgiving of a bad night, and it usually costs more. The approach also depends on skill: a frameless pack demands careful packing, a trekking-pole shelter demands a good pitch, and less insulation demands accurate forecasting. It's a good direction for most hikers and a bad destination for some.

How people actually get under ten pounds

Almost entirely through the big three. A frameless or minimal-frame pack around 2 lb, a trekking-pole shelter around 1.5 lb, and a quilt plus pad around 2.5 lb puts you at roughly 6 lb before anything else. Everything remaining has to fit into three or four pounds, which is achievable without exotic gear if the list is disciplined.

What it is not is buying the lightest version of everything you already own. The step change comes from choosing different categories of item, and each of those choices carries a real trade you should be able to name.

Where it stops being sensible

In conditions with no margin. Sustained cold, sustained rain, remote country a long way from a bail-out, or a forecast that could turn: those are the places where the comfort ultralight trades away is also the safety margin. Experienced ultralight hikers carry more in those conditions, which is the tell.

It also assumes skill. A trekking-pole shelter pitched badly in wind is worse than a cheap freestanding tent, and a thin quilt only works if you have the pad and the layering to back it up.

What this means when you're choosing

  • Pack, shelter and sleep system first, which are most of the weight
  • Whether the conditions you hike in leave room for a thinner margin
  • Durability, since ultralight gear is generally a consumable

The common mistake

Cutting the safety margin instead of the weight

The legitimate version of ultralight is lighter versions of the things you need. The dangerous version is leaving out the shell, the insulation or the light. Weight saved by not carrying warmth is not a technique, it is a gamble on the weather.

Common questions

What base weight counts as ultralight?

Under 10 lb is the usual line, with lightweight under 20 and superultralight under 5. They're conventions rather than official definitions, and nobody checks.

Is ultralight gear less safe?

It has less margin, which is a different thing. Thinner insulation and lighter shelters demand better forecasting and better skills, so the approach is safe for people who've built those and thin for people who haven't.

More in trail terms

Base weight

Base weight is everything in your pack except food, water and fuel: the gear that doesn't get used up. It's the number backpackers compare, because consumables vary with trip length while base weight is a property of your kit.

Fastpacking

Fastpacking is covering a multi-day route with a pack light enough to run in, somewhere between trail running and ultralight backpacking. Typical loads run 8 to 20 liters, and the trip is usually run downhill and on the flat and hiked uphill.

Thru-hiking

Thru-hiking is walking a long trail end to end in one continuous trip, usually within a single season. The Appalachian Trail, Pacific Crest Trail and Continental Divide Trail are the best-known examples in the US, each taking several months.

Shoulder season

The shoulder seasons are spring and autumn, the months either side of settled summer conditions. Days can be warm and nights near freezing, weather changes faster, and gear that works in July is often not enough in late September.

Three-season

Three-season gear is built for spring, summer and autumn but not sustained winter conditions. It's the default rating for most backpacking equipment, and in practice it means handling rain, wind and light frost but not deep snow.

Layering system

A layering system is the practice of combining a moisture-moving base layer, an insulating mid layer and a protective shell, so you can regulate temperature by adding and removing pieces rather than relying on one heavy garment.

Zero day

A zero day is a day on a long trail where you walk no trail miles at all, usually taken in a town to rest, resupply and deal with logistics. A nero is a near-zero: a handful of miles into or out of town with the rest of the day off.

Nero day

A nero day, short for nearly zero, is a day on a long trail when you hike only a few miles and spend the rest of it resting or doing town chores. It sits between a full hiking day and a zero day, when you hike no miles at all.

Cowboy camping

Cowboy camping is sleeping outside with no shelter over you: a pad, a bag or quilt, and the sky. It saves the weight and the time of pitching a tent, and it trades away protection from rain, wind, dew, insects and anything that walks past in the night.

Postholing

Postholing is breaking through soft snow with each step and sinking to your shin, knee or thigh, leaving a line of holes behind you. It is exhausting, it can drop your pace to under a mile an hour, and it damages the trail for everyone following.

Slickrock

Slickrock is bare, exposed sandstone with no soil on it and no tread cut into it. You walk on the rock itself and follow cairns rather than a path. Dry sandstone gives excellent grip; wet or dusty sandstone gives very little, which is where the name misleads people.

Trailhead

A trailhead is the designated access point where a trail begins, and usually where you park and start walking. Many have a map board, signs or a toilet. The US Forest Service draws a firm line: a plain junction of two trails, or of a trail and a road, is not a trailhead.

Treeline

Treeline is the elevation, or latitude, above which trees can no longer grow. It is less a line than a zone where trees shrink into stunted, wind-shaped growth, and it sits at very different heights: between 5,000 and 6,000 feet in Washington's Olympics, and above 10,000 in the Sierra.

Backcountry

Backcountry is undeveloped land away from roads and drive-in campgrounds, reached on foot or by water. In US parks it is the opposite of frontcountry, where you drive to a campground, and camping there often needs a permit. It is not the same as legally designated Wilderness.

Big three

The big three are a backpacker's shelter, sleep system and pack: the three items where most of a kit's weight sits and, as REI puts it, where you can cut the most. The usual advice is to lighten the shelter and sleep system first and choose the pack last.

Section hiking

Section hiking is completing a long trail in pieces, one stretch at a time over separate trips, rather than in one continuous push. The Appalachian Trail Conservancy counts anyone who finishes the whole trail in more than 12 months as a section hiker, and recognizes them as 2,000-milers alongside thru-hikers.

NOBO and SOBO

NOBO and SOBO are thru-hiker shorthand for northbound and southbound, the direction someone walks a long trail. On the Appalachian Trail a NOBO starts at Springer Mountain in Georgia and finishes at Katahdin in Maine, and a SOBO walks the same 2,000-plus miles the other way.

Slackpacking

Slackpacking is hiking a stretch of a long trail with only a daypack while someone else moves the rest of your gear, usually a shuttle that drops you at one road crossing and collects you at the next. You still walk every mile; you just sleep indoors and carry less.

Naismith's rule

Naismith's rule estimates how long a hike will take: one hour for every three miles of distance, plus one hour for every 2,000 feet of climbing. A Scottish mountaineer wrote it in 1892 for fit walkers taking short halts, so most people need longer.

By Tom · Last reviewed . Back to the glossary