Maker’s warranty: Limited warranty against manufacturing or material defect for the lifetime of the product; electronics up to two years; covers bought from an authorized Big Agnes retailer or direct; repair center; repair parts sold. Big Agnes’s terms, read Oct 25, 2026
A 43-liter ultralight pack from Big Agnes for fastpacking, thru-hikes and overnights, built on Big Agnes's own frame design in ultralight fabric. Big Agnes lists the S/M size at 2 lb 8 oz (1.13 kg).
Figures with a source link to the page they were read from, with the date we checked it.How we get these figures →Wrong figure? Tell us
Packs are sized by torso length, not height. How to measure yours →
Weight and price against the backpacks of 31–55 L in the RidgeNote register with a published figure; other figures against every one of the backpacks. Manufacturer-listed; sources and dates are on this page.
The lightest of the 31–55 L backpacks on record is Gossamer Gear Murmur 36 Hyperlight Backpack (Aluula) at 7.9 oz — 905 g less for $70 more.
The cheapest is Naturehike Rock 2.0 Backpack 45L at $99.99 — $180 less and 70 g heavier.
Main models on the same shelf, compared with the Sweetwater UL 43L on the makers’ published figures; the tick on each bar is the Sweetwater UL 43L.
Gossamer Gear
Gorilla 50
8.6 oz lighter (245 g)
$4.95 less
ULA Equipment
36L Patchless Ultra Dragonfly
8.9 oz lighter (251 g)
$40 more
ULA Equipment
36L ULTRA Dragonfly
8.9 oz lighter (251 g)
$40 more
Not ranked: 20 with no published volume, 1 with no published weight.
See all 26 →
Naturehike
Rock 2.0 Backpack 45L
$180 less
2.5 oz heavier (70 g)
Gossamer Gear
Aero Jet
$55 less
4.0 oz lighter (114 g)
NEMO
Resolve 35L Active Daypack (Women's)
$60 less
4.1 oz heavier (117 g)
Not ranked: 21 with no published list price, 16 with no published volume.
See all 14 →
Hyperlite Mountain Gear
Headwall 55
12 L more
1.8 oz heavier (52 g) · $195 more
Naturehike
45L Rock
2 L more
2.4 oz lighter (69 g)
Naturehike
Rock 2.0 Backpack 45L
2 L more
2.5 oz heavier (70 g) · $180 less
Not ranked: 21 with no published volume.
See all 13 →Ultralight backpacks ranked by maker-published weight: 40 models. Lightest: Gossamer Gear Murmur 36 Hyperlight Backpack (Aluula) at 7.9 oz (225 g).
Six backpacking packs from 45 to 68 L: how to fit one, then their published volume, frame, load range, weight and list price, with a reason to skip each.