10 Best Sleeping Bag Liners 2026 in the United States

The Litume All Season Fleece Sleeping Bag Liner is a cozy option designed to boost warmth by up to 27°F (15°C), which can make a big difference for colder nights while camping or backpacking. Its soft polyester fleece material feels comfortable against the skin and includes a mummy shape with a drawstring hood to trap heat efficiently. At about 85 inches long and 32 inches wide, it fits most adults up to 7 feet tall, offering good space without being bulky.

Weighing just over 1 pound (16.6 oz), it’s lightweight and comes with a compression sack, making it easy to pack and carry on trips. Another plus is that it’s machine washable, which keeps maintenance simple. On the downside, while fleece provides warmth, it’s not as breathable as some lighter fabrics, so it might feel a bit warm in milder weather or for hot sleepers. Also, the mummy design, while great for heat retention, limits movement compared to rectangular liners.

This product is ideal for campers or travelers who want extra warmth without adding much weight to their gear, especially in cold or variable conditions.

The Sea to Summit Reactor Sleeping Bag Liner in Extreme Standard size (85 x 31.5 inches) is designed to add significant warmth—up to 25°F—to your existing sleeping bag, making it a solid choice for winter campers or anyone facing cold conditions. It uses advanced Thermolite Pro fabric, which is lightweight yet insulated, thanks to hollow fibers that reflect body heat back to you. This material also stretches well, allowing good freedom of movement inside mummy-shaped sleeping bags.

The liner's drawcord footbox is a feature that lets you adjust ventilation or snugness at your feet and works seamlessly with certain Sea to Summit sleeping bags. Another practical plus is the HeiQ Fresh odor control treatment, helping the liner stay fresh even after multiple uses, which is advantageous when washing opportunities are limited. Weighing just 0.38 kg, it’s fairly light and compact for backpacking.

While it excels in warmth and hygiene, the price point is higher than simpler liners, and the fixed size may not fit everyone perfectly. Care instructions should be followed to maintain the performance and odor control of the technical fabrics. This liner provides a stretchy, warm, and odor-resistant option that works well in winter and fits mummy bags, with a higher price compared to basic models.

The Friendly Swede Extra Large Sleeping Bag Liner is made from soft microfiber with a cotton-like feel, designed to add about 10°F of warmth to your sleeping bag. Its generous size (44" x 98.5") including a pillow pocket means taller users can stretch out comfortably, making it suitable for most adults. Weighing around 23.5 ounces, it’s fairly lightweight but not ultra-light, so if you need something lighter for backpacking, there’s a polyester version available.

The full-length zipper on the side is a handy feature for easy entry and exit, and the microfiber fabric is durable and machine washable, which makes cleaning straightforward. This liner is versatile for all seasons because it helps wick away moisture in warmer weather while providing extra warmth when it’s cold. It also protects your sleeping bag from dirt, sweat, and bugs, extending its life and hygiene.

While it does add warmth, it’s not a replacement for a thicker sleeping bag in very cold conditions. It is a cozy and practical choice for campers who want a comfortable, easy-to-care-for liner that fits larger users well and works year-round.