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What Fits in an 80L Dry Bag

The physical envelope of an 80-litre bag

Picture an unrolled 80-litre roll-top and you are looking at a cylinder roughly 360 mm across and 790 mm to the brim. Run the numbers: 3.1416 x 18 squared x 79 gives about 80,400 cubic centimetres, so a label reading 80L is honest when the measurement was taken to the top edge. Empty mass follows the shell rather than the volume. A 420D TPU laminate at roughly 520 grams per square metre finishes near 850 g; the same shape in 500D TPU with a heavier base coat is about 1.05 kg; a PVC-coated 500D version lands between 1.35 and 1.5 kg because alone the coating adds around 200 g per square metre across a total wall area close to 1.0 square metre.

Those centimetres decide behaviour long before you pack anything. A diameter of 360 mm sits at the edge of what a sea kayak oval hatch will pass, because the minor axis of a standard oval hatch is commonly 300 to 360 mm. A half-full soft bag can be squeezed through a 340 mm opening, but an 80L packed to its second fold resists deformation and wedges firmly. If the plan involves pushing the bag through a hatch rather than lashing it to deck lines, dropping one size is the honest recommendation, and every handling decision afterwards follows from that single diameter figure.

Brim litres versus rolled litres: reading an 80L claim

Two conventions exist for stating capacity and the gap between them at this size is worth eleven or twelve litres. Measured to the brim, an 80L bag offers 790 mm of usable column. Fold three times and each fold consumes roughly 40 mm of that column on a supple 0.5 mm PVC film, or around 45 mm on a springier TPU laminate. That is 120 to 135 mm removed, or 12 to 14 litres deducted from the headline number. Measured from the base up to the third fold line, the same bag genuinely gives you 80 litres, and its unrolled height would instead be nearer 930 mm.

Establish which convention applies with a tape rather than a spec sheet. Stand the empty bag upright, measure from the floor to the roll line created by the stiffener, halve the circumference to get the radius, then multiply pi by radius squared by height. Around 80 litres to the fold line means you have the useful convention; 68 litres to the fold line means the headline was a brim claim. Our walk-through of the measurement arithmetic sits in the capacity measurement guide, and the roll-top capacity loss article explains why the deduction is not linear across sizes.

Clothing and soft goods: how many days fit

Soft goods are deceptive because they compress when you push them and rebound when you stop. The realistic way to budget is by item rather than by day: work out the unit volume of each garment, multiply by how many you carry, and then subtract 15 to 20% only if you have compression straps and use them consistently. A tightly rolled merino top occupies about 1.0 litre; left loosely folded in the same bag it occupies 1.6 litres, and over fifteen items that difference alone is nine litres.

The table below budgets a temperate-to-cold trip where two sets of base layers are carried for hygiene and one insulating layer is carried per person. Volumes are measured after rolling, weights are dry weights, and both assume moderate compression from packing other items on top. The seventeen to twenty-four litre range is what most seven to ten day trips need, which leaves plenty of headroom for the sleep system and shelter.

Those seven lines total about 24 litres and 4.4 kg, which is why a 10-day clothing load never fills an 80L bag on its own. What fills it is the bulky low-density layer: sleeping bags, padded jackets left uncompressed, towels, and the pile of damp swim kit nobody wants to admit to carrying. Subtract nothing for optimism when you build your own list, and remember that damp textiles gain both volume and water weight within an hour of being sealed in.

Sleep systems and shelters: the two volume hogs

Sleep insulation is the single largest consumer of space in most 80L bags. A synthetic -10 °C bag packs to roughly 18 to 20 litres and weighs around 2.4 kg; the same temperature rating in 850-fill down occupies 14 to 16 litres at about 1.9 kg, which is the upgrade worth making if space rather than cost is your constraint. A summer +5 °C bag drops to 7 or 8 litres at 0.85 kg, and a silk liner adds another 0.6 litres without ever being the thing you regret carrying.

Sleeping pads behave differently again. An inflatable R-4.5 rectangular pad rolls to about 6 litres and 0.78 kg, whereas a closed-cell foam pad cannot be compressed below roughly 8 litres for a full-length mat, though it survives sharp gravel far better. Shelter is next: a two-person three-season tent with inner, fly and poles split across two paddlers costs about 14 litres and 3.2 kg in total, or 4 litres and 0.75 kg if you swap to a tarp and two trekking poles. That choice alone frees ten litres.

Food, cooking and water: where weight overtakes space

Food is dense. A freeze-dried ration at roughly 550 grams and 1.1 litres per day means eight days of meals occupies 8.8 litres and weighs 4.4 kg, and if you choose supermarket food in tins the volume halves while the weight often doubles. A remote stove, two nested pots, a 230 g gas canister and a lighter add another 5.5 litres and 2.3 kg. Water is the heaviest item anyone carries: every litre is a kilogram, and six litres of drinking water at the start of a desert leg adds 6 kg for the first two days of walking.

This is where sizing stops being a volume exercise. At an average packing density of 0.2 kg per litre, 68 usable litres corresponds to 13.6 kg of load, and 80 usable litres corresponds to 16 kg. Both figures exceed what most people will comfortably shoulder on uneven ground for a full day, which means a full 80L bag is almost never a carried bag. It is a boat bag, a raft bag, a vehicle bag or a camp bag, and it is honest to plan around that rather than pretending it will ride on your back across a portage.

Four load-outs measured end to end

Theory gives way quickly to what people actually do with an 80L bag. The four profiles below are drawn from real trip plans and rounded to the nearest litre and half kilogram. Notice that only one of them reaches a genuinely full bag, and it is the one loaded with group catering rather than personal kit. In every other case the empty headroom exists deliberately, so the mouth can be rolled three times over air rather than over gear.

Read the last column with your own logistics in mind. Where a support vehicle can drive to the put-in, one large bag wins on simplicity. Where a trip starts with a 600 m portage or a flight, splitting into two or three bags is nearly always the better decision even though the total volume and weight go up slightly through the extra walls and closures involved.

The pattern worth memorising is that every analogue available through our roll-top dry bag range uses the same closure geometry, so a set bought as 20L, 40L and 80L can be rolled, clipped and re-used interchangeably across a whole season. Standardising on one closure means crew members can repack a bag they have never touched before without being shown how it seals.

Splitting 80 litres into manageable pieces

1. Decide whether any single item must stay accessible during the day; that item gets its own 10L to 20L bag.
2. Split remaining gear by water risk: sleeping insulation first, shelter next, clothing and food together.
3. Keep every individual bag under about 12 kg so one person can lift it with a straight back.
4. Colour-code or label each bag with its contents, not its owner, so anyone can find the stove.
5. Distribute dense items across bags so no single shell carries all the water or all the fuel.
6. Leave 8 to 10 litres of headroom in every bag for a clean three-fold closure.

Three common splits work well in practice. The 50 + 30 combination suits couples who share equipment and want one bag per person on the carry. The 60 + 20 combination suits a support vehicle where the large bag stays in the back and the small one moves with the group. The 40 + 40 combination is the safest for anything with a genuine capsize risk, because losing one half of your kit is survivable and losing all of it is not.

The cost of splitting is real but modest. A second closure adds 60 to 120 g, a third set of walls adds another 150 to 250 g, and total packed volume rises by 3 to 5 litres because two curved walls meet where one would have sufficed. Against that you gain redundancy, load distribution and the ability to hand one bag to another person when the ground turns soft.

Handle, harness and lift ratings at this size

A 40 mm webbing loop radio-frequency welded onto a 0.5 mm TPU panel can carry 60 to 80 kg in a slow static pull at 25 °C, because the load spreads across a weld area of roughly 60 square centimetres. The same loop in a jerky dynamic lift, or in 40 °C heat when the film softens, behaves very differently. Derating to a quarter of static strength gives a sensible working limit of 15 to 20 kg, which matches the loaded weights in the table above and should inform how many lift points you specify.

Two side handles beat one top handle at this size, because an 80L cylinder held by one point swings like a pendulum and drags on the ground. Shoulder straps help for a 200 m carry and then dig in; a padded harness helps to about 45 minutes. The CDC publishes guidance on safe lifting and carrying for occupational settings, and its core advice applies here too: keep the load close to your body, lift with your legs, and reduce the target weight substantially when lifting asymmetrically from a boat or a vehicle.

Packing order inside a tall narrow cylinder

Build from the bottom up by density. Sleeping insulation goes in first because it is light, bulky and benefits from being at the bottom where it forms a stable base. Then come the medium-density items: clothing rolls and the tent body. Dense, sharp-edged items such as stoves, fuel and tinned food belong in the middle rather than against the wall, wrapped in a jacket, because a metal edge working against a 0.5 mm film during transport will find the weakest point eventually.

Leave the fill below the second fold line. This is the single most common mistake at this size: a bag loaded to the third fold line physically cannot be rolled three times, so the crew closes it once, clips it, and wonders why water appeared inside after the first wave. Press the load down before the first fold, push out excess air, and only then begin rolling. A bag packed this way sits flat, stacks on deck without rolling off, and seals as designed.

Boats, hatches, roof racks and aircraft holds

Transport geometry defeats more 80L purchases than any other factor. A loaded 360 mm cylinder needs a 360 mm round or oval opening, which excludes most day-hatch and many bow-hatch configurations; check the actual minor axis of your boat before assuming the bag will go inside. On deck, an 80L bag lashed athwartships ahead of a mid-hatch is a windage problem above about 20 km/h and adds noticeable weather helm. Lashing it fore and aft behind the cockpit behaves better and keeps weight near the paddler.

For aircraft, the arithmetic is kinder. A rolled 80L at 670 mm plus 360 plus 360 gives about 1,390 mm linear, comfortably inside the 1,580 mm (62 inch) checked-bag limit most carriers apply, and the shell has no rigid frame to crack. The binding constraint is the 23 kg weight cap rather than dimensions. Our floating dry bag designs add closed-cell or trapped-air buoyancy for anyone whose bag will spend time beside a moving hull, which is worth specifying when the bag is destined for open water rather than a vehicle.

Choosing between 60L, 80L and 90L

The decision usually comes down to which constraint bites first: internal diameter for hatches, total height for a specific locker, or mass for anything lifted by one person. Sixty litres is the practical maximum for bags that need to pass through hatches or be carried on foot for an hour. Eighty litres suits boats, vehicles and group trips where two people share the lift. Ninety litres makes sense mainly for group shelter, bulky paddling equipment or a week of family kit that never has to be carried far.

Because the sizes share a closure family, moving up costs about 150 g and 60 mm of rolled height each step, which is cheap insurance against buying too small. Two people arguing between 70 and 80 should buy 80 unless a hatch diameter forbids it, and two people arguing between 80 and 90 should check the lifted load before deciding. Further reading for each end of the range is available in our guides to what fits in a 70L bag and what fits in a 90L bag.

Specifying an 80L bag for a programme

• State the capacity convention on the drawing: litres measured to the third fold line, not to the brim.
• Fix the diameter before anything else if the bag must pass through a hatch or locker.
• Specify film thickness by abrasion risk: 0.5 mm TPU for bags dragged over sand or gravel.
• Require two lift handles plus a removable harness rather than one grab loop.
• Ask for the coated-fabric test method behind any strength claim, referencing ASTM methods such as D751 where relevant.
• Set a packed-load working limit of 20 kg and print it on the hang tag.
• Colour-code across the size range so a 60L and an 80L are distinguishable from ten metres away.

Programme buyers should also check volume consistency between production runs, because a tolerance of even 3% at 80 litres shifts the packed load by more than two litres and changes whether the third fold closes cleanly. Our own production team has built waterproof bags since 2014 in an SGS-verified 4,950 m2 facility, working to AQL 2.5 inspection and running 500-piece minimum orders with sampling in 6 to 10 working days.

Finally, sanity-check the plan against the trip rather than the catalogue. If the bag will be carried more than 400 m at a time, choose 60 litres and move the rest into a second bag. If it will sit in the bottom of a raft for three days and get hosed out at the end, 80 litres in 0.5 mm TPU with welded seams will do the job for a decade with a freshwater rinse each evening.