Sleeping bags are getting lighter and more compressible as brands utilise high-loft hydrophobic down and lightweight fabrics. Choose a bag based on your budget and with a comfort temperature rating that suits the majority of your trips.

Shape 

Mummy bags are the warmest and lightest as they have less unused space. Bags vary in size and won’t suit all body shapes, so it’s best to try before buying. Some are specifically designed for women and are shorter and slightly wider at the hip.

Zips

Zips provide access and ventilation. For maximum warmth and minimum weight, half or three-quarter zips are best. A full-length, two-way zip allows greater ventilation, and same-brand bags can often be zipped together.  

Baffles

Baffles form parcels of down and place insulation where it’s most needed. In mid- to high-end bags with greater loft, baffles are separated by internal panels. On cheaper bags they’re sometimes sewn through.

Fabrics

Lightweight ripstop nylon or polyester fabrics treated with a PFC-free water repellent are common in bags with water-repellant down.

Draught tubes

Insulation-filled draught tubes prevent heat loss through zips. 

Insulation

There are two types of insulation.

Down: Whether duck or (superior) goose down, this fill is lightweight and low bulk. Most is now treated with a PFC-free water-resistant coating to maintain loft and prevent clumping when wet. Manufacturers use down that meets the Responsible Down Standard for animal welfare. 

Synthetic: This fill is good for prolonged damp conditions, lower budgets or where weight is less important. Compared to down, synthetic-filled bags are heavier and less compressible, but are more durable, easier to wash and warm when wet. 

Hood

A close-fitting hood keeps a bag warmer. A hood should have good loft, a neck baffle to trap warm air, and a drawcord that is easy to operate in the dark. 

Temperature ratings

Temperature ratings help users compare and choose the right bag for expected conditions and end use. Although three temperature ratings are used, this article refers only to two: comfort and limit temperatures.

Comfort: The temperature at which a ‘standard woman’ (25 years old, 160cm, 60kg) can expect to sleep comfortably in a relaxed position. Cold sleepers should consider this rating.

Limit: The temperature at which a ‘standard man’ (25 years old, 173cm, 73kg) can expect to sleep for eight hours in a curled position without waking. Warm sleepers should consider this rating.

Extreme: This is for when a strong sensation of cold can be expected and there is risk of hypothermia.

Unless stated otherwise, the temperature ratings for bags in this article are based on the international temperature ratings standard EN13537 or the newer ISO 23537-1.

Responsible Down Standard

All down-filled bags in this feature adhere to the Responsible Down Standard (RDS), which prohibits the removal of down and feathers from live birds. Force-feeding of birds is also prohibited. Only products with 100 per cent certified down and feathers carry the RDS logo.

Quilts

A quilt makes sense when you consider that down insulation doesn’t trap air or warmth when compressed (i.e. when you’re lying on it). Quilts have a footbox, generally extending to mid-calf, and when combined with a mattress can offer similar warmth to a sleeping bag but with reduced weight and packing size. Quilts cannot be tested to the EN or ISO temperature rating standard.

Rab Neutrino -18 $1599.95

A winter bag built with Rab’s L.O.F.T 3D technology to maximise loft, warmth and weight. It has 800g of 800FP goose down with Grangers fluorocarbon-free hydrophobic finish, longitudinal chest baffles, a 3D shaped down-filled neck collar and a two-way YKK ¾ main zip with down-filled baffle. Temp rating -18°C (comfort) Weight 1280g. www.outfitters.co.nz 

Big Agnes Fly Creek UL 25 $1199.99

A mummy fit ultralight bag for minimalist adventures. It has 482g of 850FP hydrophobic down within a quilted shell made from recycled fishing nets, streamlined hood, insulated zip and draught collar and half-length centre zip for easy temperature regulation. Temp rating 2℃ (comfort), -4℃ (limit) Weight 722g. www.bigagnes.nz 

Rab Mythic -6 $1299.95

An ultralight packable sleeping bag for multi-day trips. It has a highly tapered cut and contains 355g of 900FP goose down with Grangers fluorocarbon-free hydrophobic finish. It features heat-reflective TILT, L.O.F.T 3D construction to eliminate cold spots, a 3D shaped down-filled neck collar and an anatomically shaped foot box for relaxed sleeping posture. Temp rating -6°C (comfort) Weight 700g. www.outfitters.co.nz 

Big Agnes Torchlight EXP -7 $1099.99 (Reg)

A mummy bag with two expandable panels – from shoulder to footbox – that increase sleep space by up to 25cm. It has 510g of 650FP DownTek water-repellent down, two-way YKK #5 zipper, vaulted footbox, body-mapped baffle construction, Padlock sleeping pad attachment, snug-fit jacket-style hood, 3D anti-snag draught tube and mesh stash pocket. Temp rating -1℃ (comfort), -7℃ (limit) Weight 1130g. www.bigagnes.nz

Mont Helium 680 $1049.95

This four-season, mummy-shaped, above-the-snowline bag is Mont’s warmest in the Helium Range. It uses 680g of 800FP hydrophobic treated duck down and features dual side zippers, vertical torso baffles, a box foot, contoured hood and down-filled draught tube. Temp rating -6°C (comfort), -12°C (limit) Weight 1099g. www.mont.com.au

ONE PLANET Rumour -6 from $899

This bag has a box foot mummy shape for maximum thermal efficiency. It uses 800–850FP PFC-free hydrophobic down encased in a waterproof Pertex Quantum Pro shell with welded seams. It has vertical and horizontal baffles to prevent down migration, a contoured hood with neck baffles, a full-length water resistant YKK zip and top and bottom draught tubes. Temp rating 0℃ (comfort), -6℃ (limit) Weight 841g. www.oneplanet.au

The North Face Green Kazoo $800

A water-repellent bag made with 100% recycled materials and repurposed 700FP down. It has a fully insulated hood with cinch collar to seal in warmth, trapezoidal side-chamber baffles to reduce cold spots and retain loft, a ⅔ side zipper, and shockcords on the underside to attach a sleeping pad. Temp rating -8°C (comfort), -16°C (limit) Weight 1355g. www.thenorthface.co.nz

Mont Helium 450 $839.95

A lightweight three-to-four–season bag suitable at sub-alpine levels. There’s 450g of 800FP hydrophobic treated duck down, dual side zippers, 10D nylon fabric, a down-filled draught tube, a contoured hood and box-walled baffles. Temp rating -1℃ (w), -7°C (m) (Mont comfort ratings) Weight 850g (m), 835g (w). www.mont.com.au

Therm-A-Rest Boost 650 -6ºC $789.99 (Reg)

The temperature rating of this bag can be increased by up to 6ºC thanks to the WarmZip, which transforms it from a semi-rectangular to a mummy bag. It has 650g of 650FP hydrophobic down, a recycled soft-touch nylon shell and liner with a PFAS-free water-repellent coating, a two-way YKK anti-snag zipper, an adjustable hood, a draught tube and collar, and arm holes for freedom of movement or ventilation. Temp rating 0℃ (comfort), -6ºC (limit) Weight 1205g. www.ampro.co.nz

Marmot Wraptor -9 $799 

This 650FP hydrophobic down bag has a magnetic closure system instead of a zip. Overlapping flaps are secured by a magnet at the shoulder and snap closure at the hip. It has an envelope-style foot vent for temperature regulation and uses 100% recycled polyester shell and lining fabrics. Temp rating -5°C (comfort), -12°C (limit) Weight 1219g. www.marmotnz.co.nz 

Rab Ascent -12 $749.95 

A wide mummy-shaped bag filled with 680g of 650FP duck down with Grangers fluorocarbon-free hydrophobic finish. It has a 20D Pertex Quantum shell, a 3D shaped neck collar with recycled Stratus insulation and YKK zipped arm access vents with integrated snap closure to retain heat during tent-based tasks. Temp rating -12°C (comfort) Weight 1350g. www.outfitters.co.nz

Therm-A-Rest Boost 650 0ºC $699.99 (Reg)

This versatile bag has the WarmZip which can increase warmth by 6ºC by transforming the bag from semi-rectangular to mummy shape. It has 400g of 650FP hydrophobic down, a recycled soft-touch nylon shell and liner with a PFAS-free water-repellent coating, a two-way YKK anti-snag zipper, an adjustable hood, a draught tube and collar, and arm holes for freedom of movement or ventilation. Temp rating 5℃ (comfort), 0ºC (limit) Weight 952g. www.ampro.co.nz

Mont Zero Superlight $689.95

An ultralight two-to-three-season bag with 275g of 1000+FP goose down for use in temperatures around 2°C for a warm sleeper. There are vertical torso baffles, a contoured hood, 7D mini-ripstop downproof nylon fabric, a half side zip and hydrophobic thread (prevents moisture wicking). Temp rating 8°C (comfort – Mont comfort rating) Weight 417g. www.mont.com.au

OMM Mountain Raid 233 WP $649.99

This waterproof three-season bag is made for fast and light adventures in all weathers. It uses PointZero H2O nylon fabric with a 10,000mm waterhead rating and recycled PrimaLoft Cross-Core Gold insulation for wet weather performance, with a thicker layer on top. It has a half zip, a shaped footbox and a drawcord hood. Temp rating 11°C (comfort), 7°C (limit) Weight 640g. www.furtherfaster.co.nz

ONE PLANET Cocoon -5 from $649

This bag prioritises warmth-to-weight with a full hood and a ‘storm foot’ waterproof and windproof footbox. It uses 800–850FP PFC-free hydrophobic down and features a vertical V-baffling system to reduce down migration, a contoured full hood that cinches tight, a full-length #5 YKK zip and a draught tube. Temp rating 1℃ (comfort), -5℃ (limit) Weight 724g. www.oneplanet.au

JR Gear Helium 550 $489.99

This low-cost bag comes with 550g of down inside a 20D nylon fabric shell. It has a double side zip for easy in-out and ventilation, a warmth-trapping draught tube and full length zip, a sleeping pad pocket to prevent roll-off and a drawcord hood. Temp rating 1℃ (comfort), -5℃ (limit) Weight 1000g. www.gearshop.co.nz 

Kiwi Ultralight Down Quilt from $475

Filled with 850+FP ethically sourced goose down, it’s among the top warmth-for-weight quilts available and has a box-baffle design, a footbox section with zip closure, pad strap attachments, a neck drawstring, and 20% overfill for longevity. Comfort ratings 5℃, 0℃, -5℃ Weight From 510g. www.kiwiultralight.co.nz