🥾 How to Choose the Right Backpack Size for Day Hikes & Treks
Let me start with this: I've carried both too little and way too much on the trail—and neither is fun. On my first long hike in Himachal, I thought, “Eh, I’ll just stuff everything in this old school bag.” Big mistake. My shoulders were on fire halfway through. So yeah, backpack size? It’s everything.
Whether you're hitting a local trail for a few hours or planning a multi-day trek in the wild, finding a backpack that fits your gear—and your body—is crucial. Here’s everything I’ve learned (the hard way) about choosing the right backpack size.
🎯 Why Backpack Size Can Make or Break Your Hike
Your backpack isn’t just a sack to toss things in—it becomes part of your body out there. A poor fit or the wrong size leads to back pain, shoulder strain, or even worse, leaving something essential behind.
Here’s why getting it right matters:
- 🏋️ Even weight distribution = less fatigue
- 🛠️ Space for all your trail gear without stuffing
- 🚶♂️ Better posture, balance, and trail agility
- 😌 More comfort = more joy on the hike
👉 This highly rated hiking backpack (affiliate link) is a great place to start. It’s comfy, the size is spot-on for most folks, and the structure helps keep the load balanced.
📦 Backpack Volume: What Do “Liters” Actually Mean?
You’ll often hear hikers talk about “liters” when discussing packs. No, it’s not water capacity—it’s about total gear volume.
Quick Backpack Size Guide:
➡️ My go-to day hike pack? A 28 L bag with just enough space for food, a jacket, and my first-aid kit—but nothing bulky.
Need one that covers both short and overnight hikes? Check out this all-in-one backpack (affiliate link)—great flexibility, plus it won’t weigh you down.
🥾 Matching Pack Size to Your Hike Type
Let’s break it down so you’re not hauling a suitcase for a two-hour walk.
1. 🌄 Day Hikes (2–8 Hours)
Carry essentials like
- Hydration (bladder or 2L bottles)
- Trail snacks or a sandwich
- Lightweight rain jacket
- First-aid kit
- Map, compass, or GPS
Best pack size: 20–30 L
🧠 Pro Tip: Look for mesh back panels and padded shoulder straps—it makes a massive difference when the sun’s blazing.
2. 🌌 Overnight Hikes (1–2 Nights)
What you’ll need:
- Sleeping bag & pad
- Portable stove & fuel
- Simple meals or dry food
- Layers for nighttime chill
- Water and maybe a filter
Ideal pack size: 30–50 L
🎒 This budget-friendly backpack (affiliate link) has great compartments and compression straps. Super helpful when you're trying to keep things tight and organized.
3. 🏕️ Multi-Day Treks (3+ Nights)
Now you’ll want to pack:
- Tent or bivy
- Cooking tools
- Multiple meals
- Water filter
- Extra clothes or insulation
Go for: 50–70 L
🛑 Warning: Don’t just go for the biggest bag. You’ll be tempted to fill it, and your back will complain. Trust me.
📏 How to Fit a Backpack to Your Body
Getting the right volume is only half the battle—the real magic is in the fit.
✅ Measure Your Torso Length:
- Tilt your head and find the bump at the base of your neck (C7 vertebra).
- Place a tape between them and the line across your hips (iliac crest).
- That’s your torso length!
| Torso Length | Pack Size |
|---|---|
| < 15" | Extra Small |
| 15–17" | Small |
| 18–20" | Medium |
| 21+" | Large |
✅ Hip Size Matters Too:
Your hip belt should sit on your hip bones, not your waist. Wrap a soft tape around the top of your hips. Packs with adjustable hip belts, like this one (affiliate link), are clutch if you're in between sizes.
🔄 Backpack Fit Features You’ll Thank Yourself For
Look for these when shopping:
- ✅ Load lifters: bring the weight closer to your spine
- ✅ Sternum strap: keeps shoulder straps in place
- ✅ Adjustable torso: ideal for growing teens or in-between sizes
- ✅ Hip belt pockets: perfect for snacks and sunscreen
🎒 The pack I use right now has all of these—and no, it didn’t cost a fortune. (Check it here.)
🧳 Day Hike Essentials Checklist (What Should Fit)
Here’s a solid list to test when trying a pack out:
- 2L hydration bladder
- Sandwiches, granola bars
- Windbreaker or light rain shell
- Compact first-aid kit
- Headlamp or flashlight
- Sunscreen & bug spray
- Pocket knife or multitool
- Map/GPS/compass
- Trekking poles (strap them outside)
🧪 Real-World Test: Load up your potential pack with this gear and go walk around the block. Feel good? You’ve found your match.
🧠 Final Thoughts: Choose Wisely, Hike Happy
Your backpack is your hiking partner—it’ll either support you or make your life miserable. Pick one based on:
- The kind of hikes you do
- Your torso and hip size
- Must-carry items for your trips
Don’t get overwhelmed by options. Start simple. If you’re new, this well-balanced backpack (affiliate link) is an excellent all-rounder. It’s light, adjustable, and won’t make your wallet cry.
Happy hiking—and don’t forget to break in your gear before your trip. Your shoulders will thank you.
❓ FAQ: Backpack Size for Hiking
❓How many liters is best for a day hike?
For most people, a 20–30 L backpack is perfect for day hikes. Enough space for water, food, layers, and a few extras.
❓Can I use a school backpack for hiking?
Technically, yes, but it won’t have padded straps, load lifters, or ventilation. A hiking-specific pack is much more comfortable.
❓ How do I know if my backpack fits right?
The shoulder straps should hug your shoulders, the hip belt should sit on your hips (not your waist), and there shouldn’t be any pinching or sagging.
❓What if I’m between sizes?
Look for packs with adjustable torso lengths. Some models let you fine-tune the fit by a few inches.
