Best Ultralight Backpacks Under 1.5lb
Base-weight optimization converges on the backpack faster than almost any other gear decision. A pack that weighs 700 g before a single item is loaded sets a ceiling on the rest of the system. Every pack here weighs under 1.5 lb (680 g) by its maker’s published figure, in the size and configuration stated. Popular framed packs such as the Hyperlite Mountain Gear Southwest 40 (841.7 g), Durston Kakwa 55 (870-895 g) and Gossamer Gear Mariposa 60 (968 g) miss the line in Medium and are compared in Southwest vs Mariposa and Arc Haul vs Kakwa.
The central tension in this category is framed vs. frameless. A frameless pack saves weight but shifts the load-transfer burden onto pack contents and the shoulders. A framed pack adds structure and grams but moves more weight to the hips. Other framed packs also come in under the line. With Standard Straps, Zpacks lists the Arc Haul Ultra 40L, 50L and 70L at 597-630 g, and the Arc Pro 50L, 60L and 70L at 611-645 g in their lightest configurations ($449; the Arc Pro was added in August and September 2026). The largest Arc Pro 70L torso and belt combinations reach 683-693 g, just over the line. Gossamer Gear’s carbon-framed Mirage 40 (527 g, $450) is sold out as of October 2026. The three frameless packs here top out at about 25 lb by their makers’ figures.
Zpacks Arc Haul Ultra 60L
The Arc Haul Ultra 60L (manufacturer page) is the only framed pack in this group: 60 L at 619 g (21.8 oz). Every Standard Straps configuration lists between 594 and 665 g. The $449 Vest Straps option, a harness with built-in bottle pockets, pushes it to 684-755 g, over the line.
The curved carbon fiber Arc Frame leaves an air gap behind the back and transfers most of the weight to an interchangeable padded belt in four sizes. Torso height adjusts on three frame heights. Zpacks rates the pack at 30-35 lb for comfortable carry and 40 lb maximum, the highest rating here.
The shell is 3.3 oz/sqyd Ultra 100X, a woven UHMWPE face fabric laminated to a waterproof backing, not Dyneema Composite Fabric. All seams and attachment points are taped. Zpacks calls the pack highly water resistant but still recommends a liner. Volume is 47 L in the main body plus two 2.5 L side pockets and an 8 L mesh center pocket. At $399 it is the most expensive pack here.
Frame type: Curved carbon fiber Arc Frame.
Durston Wapta 30
The Wapta 30 (manufacturer page) is Durston’s frameless pack and the best equipped here. A complete Medium weighs 520 g (18.3 oz), including a padded, removable hipbelt with pockets, shoulder strap pockets, a sternum strap and a V-shaped top strap. With the belt and straps removed, the Medium weighs 385 g.
The body is ALUULA Graflyte V-98, a composite with a 100% UHMWPE face fabric and a heat-welded film. The main compartment is seam taped or heat bonded. Durston says it sheds nearly all water but does not guarantee it is waterproof.
Our Wapta 30 and ALUULA explainer explains the fabric construction and why it does not replace a frame.
Internal volume is 28, 30 or 32 L by torso size, plus 16 L of external pockets, for about 46 L in Medium. Durston suggests keeping loads under 25 lb (12 kg) and pitches the pack at hikers with a base weight of 10 lb or less on trips of up to seven days. It costs $299 with the hipbelt or $249 without.
Frame type: Frameless. Air mesh strips on the back panel add padding and ventilation.
Gossamer Gear Kumo 36 Superlight
The Kumo 36 (manufacturer page) is the value pick. At $180 it is the cheapest pack here; even a beltless Wapta 30 costs $69 more. A Medium weighs 567 g (20 oz) complete: a 403 g pack body, a 94 g detachable Fastbelt and a 71 g removable SitLight foam pad.
Volume is 36 L: 28 L in the main body to the extension-collar seam and 8 L in the mesh and side pockets. The fabric is 70D and 100D recycled Robic nylon, PFAS-free. Gossamer Gear makes no waterproof claim for it, so a pack liner is advisable. It is rated at 20 lb for comfort and 25 lb maximum, and comes in two torso sizes, Small (17-19 in) and Medium (19.5-21.5 in).
Frame type: Frameless, with a removable SitLight foam pad.
Hyperlite Mountain Gear Contour 35
The Contour 35 (manufacturer page) is, in HMG’s words, its simplest and lightest frameless thru-hiking pack. At 459 g (16.2 oz), Medium average, it weighs less than a complete Wapta 30 or Kumo 36. There are no stays and no foam in the back panel; contoured back seams and careful packing give it shape. HMG designs it for base weights around 10 lb and rates it up to 25 lb.
The body combines Dyneema Composite Hybrid fabrics with 100D Dyneema Gridstop and Dyneema stretch mesh. Vertical seams are taped, and the roll-top closure has a stiffener. Volume is 35 L plus 6.5 L of external pockets: shoulder strap pockets, side pockets that each take two 1 L bottles, a bottom pocket and a front mesh pocket.
The hip belt is removable 1 in webbing; a padded belt with pockets is a $29 add-on. At $350 the pack costs $51 more than a complete Wapta 30, which includes a padded belt and more external volume.
Frame type: Frameless. No stays or foam.
Closing
For base-weight optimization, the frame decision matters more than any individual spec. Three of the four packs here are frameless: the Contour 35 has the lowest complete weight, the Wapta 30 is the best equipped, and the Kumo 36 is the cheapest by a wide margin. Hikers who regularly carry more than 25 lb need a frame. The Arc Haul Ultra 60L is the framed option here, with 60 L of volume and a 40 lb rating at 619 g.