If you're new to hiking, stepping into a store or starting an online search of hiking backpacks can be daunting. Like any other product, there are multiple brands pushing colorful backpacks towards you that only slightly vary in size. Do I need a 22-liter backpack? Is 18 liters too small? The men's 35-liter backpack is the same price as the women's 30-liter, should I get that instead? Why is backpack size measured in liters?
Before you drop potentially hundreds of dollars in hiking equipment, read this guide to help you choose the right backpack size!
Day Packs: "Day pack" refers to a backpack used for a day-long hike. Any hike that isn't overnight, whether it's 1 mile or 10, is a day hike. When choosing a backpack for day hikes, I recommend that you overestimate how much space you need! When I started hiking, I used the TETON Sports 18L meaning it has an 18-liter capacity. This size backpack is great for bringing the essentials: water, a snack, keys and phone. If you are planning on walking around a local park or a smaller state park that has access to your car and water, 18-22 liters is a great size backpack.
Eventually, I got really into hiking and had more accessories to bring like a hammock, camping stove and drink set, and more emergency supplies for longer remote hikes.
For any day hike, I recommend getting a 40-liter backpack like the Maelstrom 40L Hiking Backpack. And you might ask yourself, "Why would I spend money on a hiking backpack when I have that same size backpack from work or school?" Hiking backpacks are made with different materials than the backpack you get for free from work. You'll feel the difference between a 2 pound backpack and a 4 pound backpack after hiking for a few miles!
Remember to HYDRATE! Whether you are using a water bottle, a backpack with a built-in bladder, or a backpack with water bladder routing, just make sure you hydrate! If you want to try using a water bladder, most hiking day packs come with bladder routing.
Backpacking Packs: Backpacking has its' entire own subculture in the hiking community and requires an entirely different set of hiking gear. In the case of backpacking, every ounce of weight matters, and paying extra for an ultra-lite backpack, cooking gear, sleeping gear, and clothes makes a huge difference.
Backpacking packs normally range from 50 to 80 liters, creating room for not only daily essentials and emergency supplies, but days' worth of food, clothes, and sleeping and camping equipment. Unless you're planning an overnight backpacking trip, there's no need to invest in a backpacking pack. If you want to plan a long day hike that includes cooking, a picnic, or swimming, using a larger day pack will be more convenient than a backpacking pack.
Baby Carrier Packs: Besides day packs and backpacking packs, the only time you would need a different backpack is for special circumstances like hiking with a baby or small children. Baby carrier packs can be expensive but are a great way to introduce your baby to the outdoors and hike as a family!
Conclusion: Although there are tons of different sizes of backpacks, ones with different features and hydration options, if you enjoy hiking there are at most 3 packs you would need: a day pack with a hydration system, a backpacking pack, and a carrier pack (if you want to hike with small children).
Save money by buying one day pack that will fit all your current and future needs! Instead of buying an 18, then a 22, then a 40-liter pack, choose a large daypack that will last for years. And unless you are planning a backpacking trip, don't buy a backpacking pack! Having one large day pack will suit most hikers, whether you are just starting out or planning your next 10-mile hike.
If you found this guide helpful, check out these other hiking articles from Sarah's Cozy Life: