Buying guide · 10 min read · Updated October 2, 2026

4 Best 800 Fill Down Sleeping Bags in 2026: A Practical Camping Guide

Best 800 fill down sleeping bags: two Sierra Designs 800 fill DriDown bags plus two near-fit down bags, compared on ISO ratings, weight and fit.

By Danny WalkerCamping Editor at RV Gear Lab4 products comparedSpec-sheet researched

Only the Sierra Designs listings in this set state 800 fill power, so the guide leads with two of its bags and then adds two lower-fill down bags as the nearest fits. Fill power measures loft per ounce, and 800 is the figure ultralight backpackers look for.

The two Sierra bags also print ISO comfort and limit ratings and exact trail weights, which most down listings skip. The BUERTS and Naturehike follow at 680 and 650 fill power, so expect them to be heavier for the same warmth.

RV Gear Lab field notes

The Campsite Fit Check

Start with the job: Sierra Designs Cloud 20 Degree Down Sleeping Bag leads this shortlist for Active and side sleepers. Use that fit as a reference point, then compare the alternatives against your own space and workload.
Specs that separate the picks: The first details to compare are 800 fill DriDown, 14.8 oz, 800 fill DriDown, 680FP RDS certified down. Confirm the exact model and included components before ordering.
Trade-off to plan for: No zipper to learn

Before you buy

What Matters Before You Choose an 800 Fill Down Sleeping Bag

Key buying criteria so you get the right fit the first time.

01
What 800 fill means
Fill power is how many cubic inches one ounce of down fills, so higher fill means more loft per ounce. The Sierra bags list 800, while the BUERTS lists 680 and the Naturehike 650. A higher number saves weight, not necessarily more warmth.
02
Fill weight
Warmth depends on how much down is inside as well as its quality. The Cloud Zipperless lists 14.8 oz and the BUERTS 1.76 lb. Compare fill weight alongside fill power.
03
ISO comfort and limit
ISO ratings give a comfort and a limit figure from a lab standard. The Cloud Zip lists 28F and 17F. Plan on the comfort figure for typical sleepers.
04
Zipper and shape
A zippered mummy gives ventilation and a draft collar, and a zipperless design saves weight and adds room. The Cloud Zip and Cloud Zipperless split that choice. Try to match it to your sleeping style.
05
Damp-weather care
Treated down like DriDown resists moisture better than untreated down, but all down loses loft when soaked. Pack it in a dry bag and air it daily. Store it loose at home.

Our standards

Why You Can Trust RV Gear Lab

At RV Gear Lab, we compare products based on campsite fit, verified specifications, usability, setup requirements, weight, durability, and real-world trade-offs. We do not rank products purely on marketing claims or commission rates.

We have not personally tested every product listed. Where hands-on testing is not available, recommendations are based on verified manufacturer specifications, product documentation, use-case fit, and comparative research.

How we review camping gear →

Detailed reviews

The 4 best 800 fill down sleeping bags, explained

Best Overall · 1 of 4

Sierra Designs Cloud 20 Degree Down Sleeping Bag

800 fill DriDown, 14.8 oz
ISO comfort 26F, limit 15F
1 lb 12 oz trail weight

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Best for: Active and side sleepers

Our take

The lightest 800 fill bag here, at 1 lb 12 oz, with a pad sleeve and a zipperless comforter.

Why it made the shortlist

The Sierra Designs Cloud Zipperless is a 20 degree mummy with 800 fill power DriDown, 14.8 oz of fill and 15D nylon ripstop. The listing prints ISO comfort at 26F and ISO limit at 15F, with a trail weight of 1 lb 12 oz.

Next to the Cloud Zip it saves three to five ounces and prints the warmest ISO comfort number of the two Sierra lines. An integrated comforter and a rear pad sleeve keep the bag aligned with the pad for side and active sleepers.

It suits ultralight backpackers who toss and turn and want a bed-like feel. The comforter design gives shoulders room to move.

What works

Lowest trail weight of the four
ISO comfort and limit both printed
Pad sleeve stops rolling off
Roomy comforter-style opening

Watch out for

No zipper to learn
Costs far more than the down alternatives

The catch: It has no zipper, so the opening style takes getting used to.

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Best Zippered Mummy · 2 of 4

Sierra Designs Cloud Zip 20 Degree Down Sleeping Bag

800 fill DriDown
ISO comfort 28F, limit 17F
Trail weight about 2 lb

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Best for: Traditional zip mummy fans

Our take

A full-zip 800 fill mummy with draft collar, foot vent and ISO comfort of 28F.

Why it made the shortlist

The Cloud Zip is a classic zippered mummy with 800 fill power DriDown and 15D nylon ripstop. Trail weight is 1 lb 15.1 oz with 14.74 oz of fill in one size and 2 lb 1.1 oz with 16.33 oz in the other, and ISO figures read 28F comfort and 17F limit.

The larger size carries extra fill for more room and a few more ounces.

It suits backpackers who prefer a traditional full zip with a venting foot. The collar seals warmth around the shoulders on colder nights.

What works

Draft dodger collar seals shoulders
Self-sealing foot vent
Anti-snag zipper
Printed ISO comfort and limit

Watch out for

Slightly heavier than the Cloud

The catch: Its comfort rating is two degrees warmer than the Cloud, and it weighs a few ounces more.

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Best Budget Down · 3 of 4

BUERTS Down Sleeping Bag for Adults. 680FP Ultralight Portable

680FP RDS certified down
3.13 lb, 1.76 lb fill
Packs 7 x 13.8 inches

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Best for: Budget down backpacking

Our take

RDS certified 680 fill down, 3.13 lb, with a printed 32 to 17F comfort range.

Why it made the shortlist

The BUERTS lists 680FP RDS certified down, 1.76 lb of fill and a total weight of 3.13 lb. Comfort is printed as 32 to 17F with an extreme of 10F, and the 84.6 by 32.3 inch envelope packs to 7 by 13.8 inches.

It is a step down from 800 fill, so it weighs more than a pound above the Sierra bags, and it also costs about half as much. An inner pocket and the option to zip to a second bag add practical details.

It suits budget backpackers who want RDS certified down and a clear temperature range. A 400T 20D shell is windproof and water repellent.

What works

RDS certified down fill
Comfort range and extreme printed
Inner pocket for valuables
Zips to a second bag

Watch out for

Fill power is below 800
Over a pound heavier than the Sierra bags

The catch: It is not 800 fill, and it weighs over a pound more than the Sierra bags.

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Best Value Down · 4 of 4

Naturehike 0 Degree RDS Down Mummy Sleeping Bag for Adults

650 fill RDS and IDS down
Models SP400, SP700, SP1000
Comfort 38.84 to 12.55F

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Best for: Choose-your-warmth buyers

Our take

Three warmth models of 650 fill down at the lowest price in this guide.

Why it made the shortlist

The Naturehike Snowbird is a mummy filled with RDS and IDS certified 650 fill power down, offered in SP400, SP700 and SP1000 models. The listing prints comfort temperatures of 38.84F, 18.86F and 12.55F for the three, and a note gives ISO comfort of 39F and a limit of 30F for the lightest.

It costs the least here and offers the widest choice of warmth levels, with 650 fill at the low end of this guide. A three-dimensional wind barrier, YKK two-way zipper and C-shaped pad wrap hold in heat.

It suits buyers who want to choose a warmth level and save money. The SP1000 reaches the coldest listed comfort.

What works

Three warmth models offered
Wind barrier and YKK zipper
RDS and IDS certified down

Watch out for

Fill power is only 650
Lightest model lacks neck collar

The catch: Fill power is only 650, and the SP400 lacks a U neck collar and wind strip.

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Methodology

How We Built This Shortlist

Each pick was assessed across 5 criteria weighted for real-world use.

Stated fill power

We checked which listings actually print 800 fill and flagged the lower-fill near fits.

ISO ratings

We compared printed ISO comfort and limit numbers and noted which bags give none.

Printed weight

We looked at trail weight, fill weight and packed size.

Design

We compared zippered, zipperless and envelope shapes.

Down sourcing

We noted RDS and IDS certification where the listing states it.

Decision guide

Match an 800 Fill Down Sleeping Bag to Your Camp Setup

By Sleeper Type

Your situation	Recommended pick	Why
Side or restless sleeper	Sierra Cloud Zipperless	Comforter-style opening and pad sleeve
Traditional zip fan	Sierra Cloud Zip	Anti-snag zipper and draft collar
Budget with a printed temperature range	BUERTS 680FP	32 to 17F comfort, extreme 10F
Want to pick a warmth level	Naturehike Snowbird	SP400, SP700 and SP1000 models

By Budget

Budget	Recommended pick
$90 to $140	Naturehike Snowbird or BUERTS 680FP
$230 to $240	Sierra Cloud Zipperless or Sierra Cloud Zip

800 Fill vs Lower Fill

800 Fill

The Sierra Cloud Zipperless and Sierra Cloud Zip give more loft per ounce, so they weigh under about 2 lb 2 oz. They cost more.

Lower Fill

The BUERTS 680FP and Naturehike Snowbird use 680 and 650 fill, so they need more down for the same warmth and weigh more.

Choose the Sierra Cloud Zipperless if weight is the priority, and the BUERTS 680FP if the budget is.

By Budget

Budget	Recommended pick
Lowest price	Naturehike Snowbird
Mid-price down	BUERTS 680FP
Top price, 800 fill	Sierra Cloud Zip

Ultralight Backpacking Specifically

Look for

Look for a printed trail weight and ISO figures.

In this comparison

The Sierra Cloud Zipperless prints 1 lb 12 oz with ISO 26F comfort and 15F limit.

When to Spend More

Spend more if

Spend more on a Sierra Cloud Zipperless or Sierra Cloud Zip for 800 fill and printed ISO numbers.

Save if

Save with the Naturehike Snowbird or BUERTS 680FP if you can carry a pound more.

FAQ

Before You Bring One Home

Is 800 fill down worth the extra cost?

If you count ounces, yes, because it gives more loft per ounce. If weight is secondary, a 650 or 680 fill bag costs far less.

What mistake do buyers make with fill power?

They assume higher fill means a warmer bag. Warmth also depends on fill weight and baffle design.

Is the Cloud Zipperless worth it over the Cloud Zip?

For side sleepers and ounce counters, yes, because it saves weight and keeps you on the pad. A full zipper suits those who like venting.

How do I compress a down bag for travel?

Stuff it into its sack rather than rolling it, and keep it loose between trips. Compress only for transport.

How do I wash a down bag?

Use a front-loading machine with a down-safe cleaner on a gentle cycle. Then dry on low with clean tennis balls until completely dry.

Bottom line

The short version

Browse more 800 fill down sleeping bags on Amazon →

About the author

Danny Walker

Camping Editor at RV Gear Lab

Danny covers camping gear, campsite setup, outdoor power, sleep systems and practical camping advice, with a focus on helping campers make better gear decisions.

4 Best 800 Fill Down Sleeping Bags in 2026: A Practical Camping Guide

Our top picks

The Campsite Fit Check

What Matters Before You Choose an 800 Fill Down Sleeping Bag

What 800 fill means

Fill weight

ISO comfort and limit

Zipper and shape

Damp-weather care

Why You Can Trust RV Gear Lab

The 4 best 800 fill down sleeping bags, explained

Sierra Designs Cloud 20 Degree Down Sleeping Bag

Sierra Designs Cloud Zip 20 Degree Down Sleeping Bag

BUERTS Down Sleeping Bag for Adults. 680FP Ultralight Portable

Naturehike 0 Degree RDS Down Mummy Sleeping Bag for Adults

How We Built This Shortlist

Stated fill power

ISO ratings

Printed weight

Design

Down sourcing

Match an 800 Fill Down Sleeping Bag to Your Camp Setup

By Sleeper Type

By Budget

800 Fill vs Lower Fill

By Budget

Ultralight Backpacking Specifically

When to Spend More

Before You Bring One Home

Is 800 fill down worth the extra cost?

What mistake do buyers make with fill power?

Is the Cloud Zipperless worth it over the Cloud Zip?

How do I compress a down bag for travel?

How do I wash a down bag?

The short version

Danny Walker

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