Sea to Summit
Sea to Summit Ultralight XR Insulated Air Mat (Regular)
Best use
- Made for
- Bikepacking, Backpacking and wild camping
- Not 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 3.6: too little insulation on frozen ground
From the maker's stated use and the published specs.
- Summer wild camp: 8/10 UK, roughly May to September, nights above about 8 °C, sheltered pitches.
- Three-season hills: 7/10 UK hills in spring and autumn. Wind, rain, and nights near freezing.
- Winter camp: 4/10 UK winter or high ground. Below freezing, strong wind, possibly snow. Capped at 4: needs warmth 7+ (R 4 or more).
- Weight: 8/10 How much it adds to your pack, compared with the whole market.
R-value 3.6 (ASTM).
Spring-to-autumn wild camps where nights stay above about 0 °C (R 3.6)
- Type
- Air
- R-value
- 3.6 (ASTM)
- Weight
- 415 g (Regular)
- Thickness
- 6.5 cm
- Size
- 183 x 55 cm
Packed size 1.49 L, 19 cm long and 10 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
Cotswold Outdoor £127.95 In stock. Free delivery. Free next-day delivery over £125, £6.95 under.
View at shop: Cotswold OutdoorUltralight Outdoor Gear £134.99 In stock. Free delivery.
View at shop: Ultralight Outdoor GearOutside £135 In stock. Free delivery.
View at shop: OutsidePrices 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
From maker's figures 6/10How well it stops the cold ground chilling you. 6: A bit better than average.
Sea to Summit lists R 3.6: in the R 3–3.9 band, for spring to autumn. Its product page does not name the test standard; Sea to Summit says on its site (its Comfort Plus page) that its mat R-values have used ASTM F3340 since January 2020, and Australian Geographic calls it ASTM-tested.
Thickness
From maker's figures 6/10How deep it is. Deeper is comfier, above all for side sleepers. 6: A bit better than average.
6.5 cm thick.
Quietness
From reviews 8/10How little it crinkles or squeaks when you turn over. 8: Clearly better than most.
Reviewers split a little: one hears a slight crinkle they stopped noticing after the first night, one says it stays quiet, and T3 lists 'not too noisy' as a plus.
Reviewers disagree on this.
Weight
From maker's figures 8/10How much it adds to your pack. 8: Clearly better than most.
Sea to Summit lists 415 g for the mat and 475 g with its sack. The mat sits in the 400–549 g band.
Packed size
From maker's figures 9/10How much room it takes in or on your rucksack. 9: Among the best you can buy for this.
Sea to Summit gives 19 x 10 cm and no litres: 3.1416 x 5 x 5 x 19 = 1,492 cm³, so 1.49 L, just under the 1.5 L line of the under-1.5 L 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 8/10How comfy it is, including for side sleepers.
4 reviews on comfort, e.g. "Considering the low weight and compact size, comfort was genuinely impressive.".
Stability*
Reviewers' average 9/10How well you stay on it without rolling off or bouncing.
3 reviews on stability, e.g. "Unlike thicker mats that can feel wobbly, the XR stays planted beneath you, even when side sleeping or shifting around.".
Reviewers disagree on this.
In short
Good for
- Spring-to-autumn wild camps where nights stay above about 0 °C (R 3.6)
- Backpackers who want a full-length mat at 415 g that packs to about 1.5 litres
- Side sleepers who want a light mat with some cushion
Strengths
- 415 g and a 19 x 10 cm pack for a full-length insulated mat
- Reviewers rate the comfort well for a mat only 6.5 cm thick
Weaknesses
- Only 6.5 cm thick: Better Trail called it firm rather than plush
- R 3.6 is not enough for frosty ground
- Few long-term durability reports for this new version
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.
ShowHide sources (6)
- Sea to Summit UK: Ultralight XR Insulated Air Sleeping Mat, specifications (Regular)
- SectionHiker: Review of the Sea to Summit Ultralight XR Insulated sleeping pad
- Australian Geographic: Sea to Summit Ultralight XR Insulated Mat, tested (Large size)
- Better Trail: Sea to Summit Ultralight XR Insulated sleeping pad review
- T3: Sea to Summit Ultralight XR Insulated Air Sleeping Mat review (Large size)
- Adventure Alan: Sea to Summit Ultralight XR review