When sizing a day pack, you want to aim for 20-30 liters of volume in order to carry drinking water, extra clothing, food, and other essentials. The easiest way to decide how much capacity (in liters) you need is to ask yourself how long your hikes will last. Will they be short hikes that are just a few hours in length or much longer, all-day excursions?
Shorter Hikes: 20-25 liter day packs
If your hikes will be less than 4 hours in length (a half-day), you can get a smaller volume daypack closer to 20-25 liters. For hikes close to home or within a reasonable distance to your car, you can usually just bring a map, a hat, insect repellent, sun tan lotion, a camera/phone, some snacks, a bottle of water, a light jacket, and a small first-aid kit if you’ve checked the weather forecast and it’s not going to rain. While you can get something even smaller, you can easily run out of room if you need to carry more stuff.
Here are a few packs that are good for shorter hikes:
Longer Hikes: 26-30 liter day packs
For hikes lasting 6-8 hours or more (a full day), I’d get something larger, in the 26-30 liter range. On longer, full-day hikes, ones farther from shelter, or where weather conditions are more variable, you want to carry all of the above, plus more water, more food, a warmer jacket, a rain jacket, and rain pants, which will be much heavier and require more volume to carry. For example, a liter/quart of water weighs 2 lbs, which really adds up if you carry 2 or 3 liters of water on a longer day hike.
Here are some good packs for full day hikes:
Higher volume daypacks, in the 26-30 liter range also tend to have a stiffer back panel (frame) or even a hip belt so all the weight isn’t on your shoulders but is also carried by your legs. In contrast, small backpacks (in the 20-25 liter range) often lack a hip belt or just come with a webbing strap designed to keep the pack from bouncing against your back when you hike. It varies by make and model, but these are things to look out for.
Winter Day Packs
If you also intend to hike, snowshoe, or ice climb in winter, you might want to get a second, even larger backpack that is between 30 and 40 liters in size. Winter clothing is heavy and bulky while traction aids like snowshoes, microspikes, and crampons are quite heavy. For example, snowshoes weigh between 4 and 5 pounds per pair, so you’ll want a daypack with a frame and a beefier hipbelt that provides more support.
Here are some good packs for winter days hikes:
- REI Traverse 32 Pack
- Osprey Mutant 38 Backpack
- Mountain Hardwear Scrambler 35L Pack
- Hyperlite Mountain Gear 2400 Ice Pack
Updated Feb 2023.SectionHiker is reader-supported. We independently research, test, and rate the best products. We only make money if you purchase a product through our affiliate links. Help us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.
Yeah, I have a 25, a 30 and a 40 depending on where and when. The wee 25 litre is a handy vaude and very comfy. It compresses small as well.
Most of my day hikes are hill walks for context.
I didn’t know about Vaude until I saw your mention of the brand. I really like the looks of the Brenta 30.
I use one 33 liter for everything. 3 day backpacking trip no problem and day hikes I have everything with me no need to thing of what to drop.
I use an REI 22 L Flash for almost all day hikes (SE US). Sometimes I’ll carry my 38L frameless (main) pack for 20+ mi day hikes mostly to get reps in near my 3 day pack weight.
I use a 40liter pack for all day walks regardless. Plenty of room for wet weather gear, food, camera, binos, a fleece jersey, 2 liters of water, vacuum flask of hot water. It all fits in.
Has a waist belt, sternum strap, good padding and is canvas.
Even has loops for hiking poles or ice axe.
A really good size unless your going ultra lite.
I use a 38L usually. Plenty of room for fishing gear, water, food, fleece, puffy (in mountains) etc. Hip belt, lightweight frame. Even sturdy enough to carry snowshoes and crampons in winter.
Which 38 L? I just got the Mystery Ranch Scree 32 for a similar use case. A do so it all pack that can carry snowshoes, telephoto camera lenses, winter kit, or trail building tools. I really like that they have a orange colorway which is great both recreationally and at work as an Ecologist during hunting season.
You spelt litre’s wrong. ?
Liter=Litre. One is not more right than the other, just depends on where you’re from and they both mean the same thing.
Liter is American(ized) spelling, Litre is International. Derived from Litron, an old French unit of measurement. Wikipedia…
The REI Trail 40 has turned into a good day pack for me. I live in SoCal, and until recently, water sources have been scarce. The 40 liter capacity, and ample padding in the hip belt and shoulder straps allows me to carry all the water I need. It also accommodates bulky winter clothing (still transitioning to lighter/ultralight gear). Good for a fully-packed overnighter, too!
I have been using the18 liter Patagonia Slope Runner this winter and I’m very pleased with it on established trails. If I need to carry a lot of safety gear I grab my Osprey Stratus 36.
I have a Nashville Packs Tiempo which I am enjoying a lot – it is great for dayhikes where you want to travel fast and light. Lots of stretchy pockets on the straps, so many smaller items can be close at hand. Strap system is super comfortable. Holds 17 liters. https://nashvillepack.com/collections/packs-and-straps/products/the-tiempo-pack
I’ve found that if I pour something from a 1.75 L into a smaller container, it’s usually about right for a day pack…
True. Some days I take a pad, blanket or bag, and a small shelter. Rain or shine, summer or winter. Totally chilled out in nature for a couple hours, sublimity.