Trampers are fortunate to have a huge range of sleeping bags to choose from. Use this guide to help narrow down your choices.
There are two two types of insulation:
Down: The best for weight and bulk. Most down is now treated with a water-resistant coating to maintain loft and prevent clumping when wet. Check the label to make sure the down is dry treated. Most manufacturers use down that meets the Responsible Down Standard for animal welfare.
Synthetic: A good option for prolonged damp conditions, lower budgets or where weight is less important. The bags are heavier and less compressible than down for the same warmth rating but are durable, easier to wash and they’ll be warmer when wet. High-end and budget synthetic bags are available.
The fill power (or loft) of a bag indicates the insulative quality of the down in the bag. Bags with high fill power numbers, e.g. 850FP, use less down to achieve the same warmth as a bag of, say, 600FP which will be heavier and less compressible. The higher the fill power, the more expensive the bag.
Ratings are approximate, however, bags in this feature have all been tested to the temperature ratings standard EN13537 or, for bags sold outside Europe, ISO 23537-1. The temperature ratings shown are:
Comfort: The temperature a user, in a relaxed posture, could expect a comfortable night’s sleep.
Limit: The temperature at which a user with a curled body position is in thermal equilibrium and does not feel the cold.
Extreme: A strong sensation of cold can be expected and there is risk of hypothermia.
The more anatomic and better fitting the hood, the warmer the bag will be when pushed to its limit. Hoods should have good loft and a neck baffle to trap warm air. Drawcords should be easy to operate in the dark.
Mummy bags are the warmest and lightest due to there being less ‘dead space’. Bags vary in size, so it’s best to try a couple to see which suits your body shape. Women-specific bags are shorter and slightly wider at the hip.
Zips allow ease of entry and ventilation. For maximum warmth and minimum weight, half or three quarter zips are best. A bag with a full length, two-way zip allows for greater ventilation and can sometimes be zipped to another bag.
Baffles form the parcels of down and are distributed to place the insulation where it’s needed most. In mid to high-end bags, baffles are separated by internal panels for greater loft. On cheaper bags, they’re sometimes ‘sewn through’.
DWR-treated ripstop nylon or polyester are the most common shell fabrics. With down now usually dry treated, lighter fabrics have made a comeback.
Insulation-filled draft tubes prevent heat loss through the zip.
Now you know what to look for, in descending price order here are some of 2023’s best sleeping bags:
Rab Mythic 600 $1699.95
An ultralight four-season bag with a highly tapered cut and chevron-shaped baffles to keep the 900FP Nikwax hydrophobic goose down in position. There is an adjustable neck baffle, a three-quarter length zip, and an angled footbox for relaxed sleeping posture. Fill weight 600g Temp rating -5°C (comfort), -12°C (limit), -32°C (extreme) Weight 885g. www.outfitters.net.
Rab Mythic Ultra 360 $1499.95
This alpine and fast-packer bag has a good warmth-to-weight ratio thanks to its heat-reflective Thermo Ionic Lining combined with 900FP Nikwax hydrophobic goose down. It has a half-length zip, ergonomic internal collar and hood and angled foot box. Fill weight 360g Temp rating -2°C (comfort), -8°C (limit), -27°C (extreme) Weight 606g. www.outfitters.net.nz
Therm-a-Rest Hyperion 20°F/-6°C $1229 (reg)
This three-season bag is among the lightest in its class. It uses 900FP Nikwax hydrophobic down and thermally-efficient box baffled construction in key areas for warmth and comfort. SynergyLink Connectors can secure the bag to a mattress for comfort and thermal efficiency. Fill weight 360g Temp rating 0°C (comfort), -6°C (limit), -23°C (extreme) Weight 567g. www.ampro.co.nz
Rab Neutrino Pro 500 $1099.95
A three-season bag for fast and light mountain missions. It uses 800FP Nikwax hydrophobic goose down encased in a wind and water-resistant recycled Pertex Quantum Pro fabric. There are weight-saving chevron baffles, a three-quarter length zip, and an adjustable hood. Fill weight 500g Temp rating 0°C (comfort), -6°C (limit), -24°C (extreme) Weight 915g. www.outfitters.net.nz
Therm-a-Rest Parsec 20°F/-6°C $1099 (reg)
A bag designed for lightweight packability and use from early spring to late autumn. It’s filled with 800FP Nikwax hydrophobic down and has a soft-touch 20D 100% recycled nylon shell and liner. An ergonomic toe box helps warm cold feet and SynergyLink Connectors can secure the bag to a pad for greater thermal efficiency. Fill weight 470g Temp rating 0°C (comfort), -6°C (limit), -23°C (extreme) Weight 805g. www.ampro.co.nz
Mont Helium 680 $989.50
This four-season, mummy-shaped above-the-snowline bag is Mont’s warmest in the Helium Range. It uses 800FP hydrophobic treated white duck down and features dual side zippers, vertical torso baffles, a box foot, contoured hood and down-filled draft tube. Fill weight 680g Temp rating -6°C (comfort), -12°C (limit) Weight 1099g. www.mont.com.au
Big Agnes Pluton UL 40 $949
This is a highly compressible, ultralight bag using 850FP water-resistant DownTek insulation. It has a minimalist hood with one-handed drawcord, a full-length zipper that can be opened up for quilt use and an ergonomic footbox. Fill weight 227g Temp rating 4°C Weight 454g. www.gearshop.co.nz
Rab Ascent Pro 800 $899.95
A generous-fit winter bag with 650FP Nikwax hydrophobic duck-down and a wind and water-resistant Pertex Quantum Pro outer. It will cope with wind, condensation and damp conditions. Fill weight 800g Temp rating -15°C Weight 1430g (m), 1350g (w). www.outfitters.net.nz
Big Agnes Star Fire UL $879.99
This is Big Agnes’s most compressible technical bag. It’s filled with 850FP DownTek water-repellent down and has a Pertex shell. There’s body-mapped baffle construction, an anti-snag draft tube, contoured hood and ergonomic footbox. Fill weight 284g Temp rating -1°C Weight 652g. www.gearshop.co.nz
Big Agnes Torchlight UL $829.99
A mummy bag with two expandable panels from shoulder to footbox that add an extra 25cm to the sleep space and allow for a customised fit. It uses 850FP water-repellent DownTek insulation, there’s a jacket-style hood, thermally efficient body-mapped baffles, and a vaulted footbox. Fill weight 312g Temp rating -1°C Weight 794g. www.gearshop.co.nz
Therm-a-Rest Questar 32°F/0°C $799.99 (reg)
This is the lightest bag in the Questar range. It uses 650FP Nikwax hydrophobic down that is claimed to stay drier and maintain loft 60 times longer than untreated down. It has zoned insulation, which saves weight and maximises warmth. There’s a heat-trapping draft collar, full-length zipper draft tube, snag-free zipper and cinchable hood. Fill weight 400g Temp rating 5°C (comfort), 0°C (limit), -15°C (extreme) Weight 849g. www.ampro.co.nz
Rab Alpine 600 $799.95
A tapered three-season alpine and tramping bag with 650FP Nikwax hydrophobic duck-down fill. There’s a wind-resistant Pertex Quantum outer, chevron baffle design for down stability and even distribution, a three-quarter length zip, down-filled neck collar and angled footbox. Fill weight 600g Temp rating -5°C (comfort), -12°C (limit), -32°C (extreme) Weight 1050g (m), 1000g (w). www.outfitters.net.nz
The North Face Blue Kazoo Eco $750
A water-repellent bag made with recycled materials and repurposed 700FP goose down insulation. It has trapezoidal side-chamber baffles,, and the hood is fully insulated with a cinch collar. There’s a two-thirds length side zipper and mattress attachments. Fill weight N/A Temp rating 0°C (comfort), -6°C (limit), -24°C (extreme) Weight 800g. www.thenorthface.co.nz
Mont Helium 450 $749.95
A lightweight 3-4 season bag suitable at sub-alpine levels. It uses 800FP hydrophobic treated white duck down and features dual side zippers, 10D nylon fabric, down-filled draft tube, contoured hood and box-walled baffles. Fill weight 450g Temp rating -1°C (comfort), -7°C (limit) Weight 850g (m), 835g (w). www.mont.com.au
Marmot Sawtooth $699
A cold-season bag with fluffy 650FP duck down treated with hydrophobic Down Defender. It has a footbox zipper for ventilation and dual side zips with extended flaps for cold-night coverage. It’s made from recycled fabrics. Fill weight 700g Temp rating -3°C (comfort), -9°C (limit), -28°C (extreme) Weight 1310g. www.marmotnz.co.nz
Exped Trekkinglite -10C from $649.99
This 700FP European duck down bag offers excellent warmth-to-weight and a minimal packed size for spring through winter trips. It’s a bag for warmer sleepers, with cold sleepers finding it more suitable for spring and summer. It has a proportional differential cut, multi-chambered footbox and a plush adjustable draft collar, all contributing to its warmth rating. Fill weight 770g Temp rating -5°C (comfort), -11°C (limit), -32°C (extreme) Weight 1290g. www.bivouac.co.nz
Mont Zero Superlight $629.95
An ultralight 2-3 season bag with 1000FP goose down that is appropriate for temperatures to around 2°C for a warm sleeper. Features include vertical baffles for down distribution on the torso, a contoured hood, 7D mini-ripstop downproof nylon fabric, half side zip and hydrophobic thread (prevents moisture wicking into the bag). Fill weight 230g Temp rating 8°C (comfort), 2°C (limit) Weight 417g. www.mont.com.au
Nemo Riff 15 $599.95
This is a spoon-shaped bag with extra room at the elbows and knees to better accommodate side sleepers. It uses 800FP hydrophobic down and has two zippered chest vents to help regulate temperature during the night. There’s a ‘Blanket Fold’ external draft collar, and a full-length zip enabling men’s and women’s bags to be zipped together. Fill weight 540g Temp rating -2°C (comfort), -9°C (limit) Weight 1080g (m), 1330g (w). www.mountainadventure.co.nz
Big Agnes Fussell UL DownTek Quilt $579.99
A three-season quilt for hut trips and thru-hikes, or to pair with another bag for additional warmth. It uses 850FP DownTek insulation and is designed to be tucked around the user. 10 snap patches create a simplified mummy bag on cold nights or allow the quilt to be fixed to a sleeping mat. Fill weight 255g Temp rating N/A Weight 582g. www.gearshop.co.nz
Marmot Women’s Angel Fire $549
A women-specific, shoulder season, bag with 650FP duck down treated with hydrophobic Down Defender. It has a footbox zipper for ventilation and dual side zips with extended zipper flaps for cold-night coverage. It’s made from recycled fabrics. Fill weight 710g Temp rating -3°C (comfort), -9°C (limit), -28°C (extreme) Weight 1270g. www.marmotnz.co.nz
Sierra Designs Nitro Quilt 20 $549
This is one part blanket, one part sleeping bag and is designed for those looking to cut pack weight or who feel restricted by mummy bags. It has an oversized fit and overall larger size for greater coverage, and uses water-resistant 800FP DriDown. There are full-length insulated hand/arm pockets and a hideaway hood to contain warmth on cold nights. Fill weight 420g Temp rating 0° (comfort), -6° (limit) Weight 760g. www.furtherfaster.co.nz
Exped Lite +1 from $499.99
This is a lightweight bag with velvety soft inner and outer fabrics. It is also watertight and has an 800FP European goose down fill, a radical differential cut to prevent elbows and knees compressing the down, a-retention comfort hood, mattress loops and 3D footbox. Fill weight 310g Temp rating 6°C (comfort), 0°C (limit), -16°C (extreme) Weight 780g. www.bivouac.co.nz
Sierra Designs Cloud 20 Women’s $499
A zipperless sleeping bag with unrestricted freedom for any sleeping position. It’s shaped for women (there’s a men’s version, too) and uses water-resistant 800FP DriDown and warmth features like an adjustable self-sealing foot vent, insulated shoulder pockets and a sleeping pad sleeve. Fill weight 580g Temp rating -6° (comfort), -13° (limit) Weight 1030g. www.furtherfaster.co.nz
Marmot Trestles Elite Eco 20 $349.95
Marmot says this is its most sustainable sleeping bag. It features Marmot Upcycle PFC-free and recycled shell, lining and fill. The synthetic insulation blends three fibres for warmth, softness and high loft. There’s wave construction on top for loft and warmth, and blanket construction on the bottom for comfort. Fill weight 710g Temp rating 0.1°C (comfort), -5.8 °C (limit), -23.2°C (extreme) Weight 1292g (m), 1214g (w). www.marmotnz.co.nz
Marmot Trestles Elite Eco 30 $299.95
This mummy-style bag is made from 96% recycled material and its synthetic insulation blends three fibres for warmth, softness and high loft. There’s wave construction on top for loft and warmth, and blanket construction on the bottom for comfort. Fill weight 490g Temp rating 3.1°C (comfort), -2.2 °C (limit), -18.5°C (extreme) Weight 490g (m), 775g (w). www.marmotnz.co.nz