Rab
Rab Ultrasphere 5 Sleep Mat (Regular, 183 x 51 cm, 2026 version)
Best use
- Made for
- Bikepacking, Backpacking and wild camping
- Also works for
- Winter mountain
Why these labels
- Bikepacking: The maker states this use, and the published specs do not rule it out.
- Backpacking and wild camping: The maker states this use, and the published specs do not rule it out.
- Winter mountain: R-value 5.5
From the maker's stated use and the published specs.
- Summer wild camp: 9/10 UK, roughly May to September, nights above about 8 °C, sheltered pitches.
- Three-season hills: 8/10 UK hills in spring and autumn. Wind, rain, and nights near freezing.
- Winter camp: 8/10 UK winter or high ground. Below freezing, strong wind, possibly snow.
- Weight: 9/10 How much it adds to your pack, compared with the whole market.
R-value 5.5.
Lowest price we found
£154.99 at Ultralight Outdoor Gear
Go to Ultralight Outdoor Gear Compare 2 shopsFast-and-light three-season backpacking, bikepacking and long-distance walking where pack space is tight
- Valve
- two-way valve
- Type
- Air
- R-value
- 5.5 (not ASTM)
- Weight
- 345 g (Regular)
- Thickness
- 8 cm
- Size
- 183 x 51 cm
Packed size 0.95 L, 15 cm long and 9 cm across Compare with a 2-litre bottle
Shorter than a 2-litre bottle and about as wide as one. Drawn to scale.
Where to buy
Ultralight Outdoor Gear £154.99 In stock. Free delivery. Free UK delivery over £15.
View at shop: Ultralight Outdoor GearRab £170 In stock. Free delivery.
View at shop: RabCotswold Outdoor £152.95 Out of stock. Low in stock. Shows £170 RRP with 10% off; free next-day delivery over £125.
View at shop: Cotswold OutdoorPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Warmth
Estimate from maker's specs: maker's R-value (not ASTM tested) 8/10How well it stops the cold ground chilling you. 8: Clearly better than most.
Estimate from maker's specs
Thickness
From maker's figures 8/10How deep it is. Deeper is comfier, above all for side sleepers. 8: Clearly better than most.
8 cm thick.
Quietness
Estimate: only 1 review about noise (fewer than the 3 we need, so never above 8) 8/10How little it crinkles or squeaks when you turn over. 8: Clearly better than most.
One reviewer found it quiet, with the crinkle from turning over well suppressed.
Weight
From maker's figures 9/10How much it adds to your pack. 9: Among the best you can buy for this.
345 g (Rab, Regular) is under the 400 g line.
Packed size
From maker's figures 10/10How much room it takes in or on your rucksack. 10: The best you can buy for this.
Rab gives a packed size of 15 x 9 cm: 3.1416 x 4.5 x 4.5 x 15 = 954 cm3, about 0.95 L, under 1.5 L. GearJunkie lists 18 x 9 cm (about 1.1 L): same band.
What reviewers say (out of 10)
Ratings marked * are from reviews and are not part of the trip score. They are reviewers' scores, not our own measurements. How we score
Comfort*
Reviewers' average 9/10How comfy it is, including for side sleepers.
4 reviews on comfort, e.g. "cuts down on weight and space while still offering a highly comfortable pad.".
Stability*
Reviewers' average 7/10How well you stay on it without rolling off or bouncing.
3 reviews on stability, e.g. "This one was spacious enough, though, that I wasn’t constantly spilling off of it.".
Durability*
Reviewers' average 7/10How well it resists punctures, leaks and worn valves over seasons of use.
3 reviews on durability, e.g. "Even with my dogs lounging on the pad, it suffered no noticeable damage.".
In short
Good for
- Fast-and-light three-season backpacking, bikepacking and long-distance walking where pack space is tight
- Side and stomach sleepers who want 8 cm of cushioning in under 350 g
- Light sleepers: reviewers found it quiet
Strengths
- 345 g and about 0.95 L packed (Rab figures): about the size of a drinks can
- 8 cm thick, quiet fabric with horizontal baffles that reviewers found comfortable
- Pump sack, two-way valve and repair kit included
Weaknesses
- Warmth is an estimate, not a reviewed score: Rab says R 5.5 without naming a test standard, Cotswold Outdoor lists 4.9, and GearJunkie felt cold near freezing even in a winter bag
- 20D fabric on both sides: Outdoor Gearzine says use it inside the tent or on a groundsheet over rough ground
- Hard to roll back into its small stuff sack (GearJunkie)
- No long-term durability reports yet for this 2026 version
- Tapered mummy shape is narrower at the feet than a rectangular mat
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.
ShowHide sources (7)
- Rab: Ultrasphere 5 Sleep Mat product page (UK)
- GearJunkie: The Rab Ultrasphere 5 Sleep Mat Review (fall and spring trips, Illinois and Kentucky)
- Outdoor Gearzine (Japan): Rab Ultrasphere 5 practical review (in Japanese)
- Justin Outdoors: I Tested New Ultralight Gear (overnight in the Canadian Rockies, Ultrasphere 5 segment)
- Cotswold Outdoor: Rab Ultrasphere 5 Sleeping Mat product page (lists R 4.9, 345 g)
- Backpacker: The Best Backpacking Sleeping Pads of 2026 (Rab Ultrasphere 5)
- YAMA HACK (Japan): Rab Ultrasphere 5 field review, page 2 of 2 (in Japanese; Wide size tested, July heat)