What Size Backpack for a 3-Day Hike?

Planning a three-day hike is exciting. You’ll spend a few days outdoors, soaking up fresh air, and exploring nature. But before you lace up your boots, there’s one important question you face: what size backpack do you need for a 3-day hike?

Choosing the right backpack size isn’t just about comfort; it can make or break your trip. Too small, and you’ll struggle to fit the essentials. Too big, and you’ll carry extra weight that slows you down.

In this blog, we’ll break down everything you need to know about choosing the right backpack size for a 3-day hike, factors that affect backpack size, packing tips, and more. Read on to find out!

Understanding Backpack Sizes

When we talk about backpack “size,” we’re usually referring to its capacity, measured in liters (L). Instead of focusing on how tall or wide the pack looks, think about how many liters of gear it can hold. For reference:

• Daypacks are usually 20–35L.
• Overnight or weekend backpacks are 35–50L.
• Multi-day backpacks are 50–70L (or more for long expeditions).

Typical Backpack Sizes for a 3-Day Hike

For a 3-day hike, the ideal hiking backpack size typically ranges from 40 to 65 liters, depending on your gear, hiking style, and the season. Here’s a general breakdown of what works for most hikers:

• 40–45L backpacks are best for ultralight or minimalist hikers. They’re an excellent choice for warmer-weather trips since you won’t need to carry as much clothing or gear.

• 50–55L backpacks are the most common choice for 3-day hikes. They provide enough space for a tent, sleeping bag, food, clothing, and extras without being too bulky

• 60–65L hiking backpacks: If you’re carrying winter gear, group cooking equipment, or extra comfort items, a 60–65L hiking backpack is an ideal choice.

Is a 40L Backpack Enough for a 3-Day Hike?

A 40L pack can work for a 3-day hike if you’re an ultralight hiker, traveling in warmer weather, and don’t need bulky camping gear. Here’s what you can fit in a 40L backpack while keeping it light and efficient:

1. Shelter & Sleep

• Lightweight tent or tarp (if camping) – consider ultralight models
• Sleeping bag or quilt (compact, rated for the season)
• Sleeping pad (inflatable or foam)

2. Clothing

• 2–3 moisture-wicking base layers (tops & bottoms)
• 1 insulating layer (fleece or lightweight down jacket)
• 1 rain jacket or shell
• 3 pairs of underwear & socks
• Hat, gloves (season-dependent)

3. Food & Water

• 3 days of dehydrated or lightweight meals
• Snacks (trail mix, energy bars)
• 1–2L water reservoir or bottles (you can refill from streams with a filter)

4. Cooking & Essentials

• Spoon/fork, small knife
• Lighter or matches
• Food storage bag, if needed for wildlife

5. Navigation & Safety

• Map, compass, or GPS
• Headlamp or small flashlight
• First aid kit (compact)
• A small knife
• Sunscreen, bug repellent

6. Extras (Optional, if space allows)

• Phone + power bank
• Bandana
• Trekking poles (if not strapped outside)

Factors That Influence Backpack Size

Image Source: Glux® Outdoor Hiking Backpack Collection

1. Your Packing Style

Are you a minimalist who travels light, or do you like to bring extra comfort items? You can get away with a 40–50L backpack if you’re okay with carrying only the basics like a lightweight tent, compact sleeping bag, and dehydrated meals. 

On the contrary, if you like to pack extras like a camping chair, heavier cookware, or multiple outfit changes, you’ll need a 55–65L backpack.

2. The Season and Weather

Cold-weather hiking usually means more gear. A winter sleeping bag, insulated clothing, and a thicker tent take up more space. For summer hikes, lighter gear reduces your volume needs. Therefore, a 60L+ backpack is better in winter.

3. Your Food and Water Needs

Three days means carrying at least 6–9 meals, snacks, and sometimes extra water storage. If you’re hiking in an area with plenty of water sources, a smaller pack works since you’ll just carry a filter. But if it’s dry terrain, extra water capacity means you’ll need a larger pack.

4. Gear Quality and Size

Modern ultralight gear can save you a ton of space. For example, a compact 1-person tent packs down much smaller than a budget 2-person tent. If your gear is older or bulkier, you’ll want more liters in your pack.

Top Backpack Picks for Your 3-Day Hiking Adventure

1. Glux® 40L Tactical Backpack for 3-Day Hiking 

2. Glux® 40L Waterproof Backpack for 3-Day Hiking

3. Glux® 40L Hiking Backpack with Removable Rain Cover

4. Glux® Glux® Hiking Waist Pack

Image Source: Glux® Hiking Waist Pack to Complete Your Backpacks

A small, lightweight waist pack for hiking adds convenience and makes your hike more comfortable. It keeps small essentials within easy reach. When you set up camp and want to explore nearby trails, you can leave the bigger backpack behind and carry just the waist pack.

🔥🔥🔥Explore More Glux Hiking Backpacks. 

How to Pack Smart for a 3-Day Hike

Getting the right backpack size is only half the equation. Here, we’ll share some extra tips to help you pack smart, save space, and stay comfortable on your hike.

• Sleeping Gear: Compress them into stuff sacks and place them at the bottom of your pack. Either attach sleeping pads to the outside to save internal space.

• Shelter: Split the load if you’re hiking with a partner. One person carries the tent body, and the other carries poles and stakes.

• Clothing: When you’re hiking on cool days, stick to layering: a moisture-wicking base, an insulating mid-layer, and a waterproof outer shell like a hiking jacket. Roll clothes tightly or use packing cubes.

 

• Food and Cooking Supplies: Dehydrated meals are a space saver and lighter to carry. Store your food in odor-proof bags and place them in the middle of your pack for balance.

• Water: Carry at least 2 liters in a hydration bladder or bottles. If water is scarce, plan to bring more or carry collapsible containers.

• Essentials: First aid kit, map, compass or GPS, headlamp, multi-tool, and toiletries all add up. Pack them in accessible compartments.

Comfort and Fit Matter Too

A poorly fitted 50L pack can feel worse than a properly fitted 60L. A well-fitted backpack distributes weight onto your hips, not just your shoulders. When trying on packs:

• Adjust the hip belt so it sits snugly on your hip bones.
• Tighten shoulder straps without digging into your shoulders.
• Use load-lifter straps to pull the weight closer to your back.

Mistakes to Avoid When Choosing a Backpack

A lot of hikers learn the hard way. Here are some pitfalls to avoid:

• Going too big: A 70L+ pack for a three-day hike usually means you’ll pack unnecessary items. Bigger isn’t always better.
• Going too small: Trying to squeeze three days of gear into a 35L pack often leads to strapping items awkwardly on the outside, which throws off balance.
• Skipping a test run: Always try your packed backpack on a short hike before heading out. It’s the best way to catch issues early.

Extra Tips for a Smooth 3-Day Hike

• Plan your meals ahead. This avoids carrying excess food.
• Check the weather. Knowing if it’ll rain or drop cold helps you pack smarter.
• Use compression sacks. They save space and keep gear dry.
• Keep essentials accessible. Things like rain gear, snacks, and maps should be in side or top pockets.

So, What’s the Best Backpack Size for a 3-Day Hike?

For most people, the 50–55L range backpack is ideal. It gives you enough space for shelter, sleeping gear, food, and clothing without weighing you down. If you’re an ultralight hiker, you can get away with 40–45L. If you’re carrying bulkier gear or hiking in winter, go with 60–65L.

Hit the trail with confidence with Glux backpacks. Our backpacks carry everything you need to stay safe, comfortable, and fueled for adventure, without the distraction of sore shoulders. With Glux backpacks, three days in the wild will feel a lot better.