Wait! What does a 45L backpack mean!?
If you’ve ever stared at a packing list and wondered what those numbers actually mean, you’re not alone.
Most of the women’s active travel tours we organize include some form of hiking. These hikes range from easy to strenuous and from less than one mile to the iconic 40-mile Laugavegur Trek in Iceland. Each tour itinerary clearly outlines the hikes involved, including distance and difficulty. With every hike, one thing is consistent: you’ll need a backpack.
So how do you know what size backpack you actually need? With hundreds of options available, choosing the right one can feel overwhelming. This guide breaks it down clearly and explains what does a 45L backpack mean, why it’s so commonly recommended, and how to choose the best backpack size for women on active travel tours.
48L Backpack example on Women’s Laugavegur Trek
Functionality: What Your Backpack Needs to Do
The primary job of your backpack isn’t just to carry your gear — it needs to perform well in the environments where you’re traveling. No matter the hike length, your women’s hiking backpack should include:
- A rain cover
- A waist (hip) strap
- Proper fit for your body
- Durable materials (no holes, fraying straps, or broken buckles)
Before trying on packs at REI or another outfitter, it’s important to understand backpack sizes explained in liters — because size matters more than brand.
Measuring Backpack Size (Liters Explained)
Backpacks are measured in liters, typically ranging from very small day packs to extremely large expedition packs (100L+). For the types of trips we offer, you will never need a pack anywhere near that large. We always specify the appropriate size in our packing lists.
If your backpack doesn’t list its liter size (common with older or hand-me-down packs), you can calculate it:
- Measure the length × width × depth (in inches)
- Multiply those numbers to get cubic inches
- Divide by 61 (the number of cubic inches in one liter)
Example:
14″ (L) × 12″ (W) = 168
168 × 22″ (D) = 3,696 cubic inches
3,696 ÷ 61 ≈ 60L backpack
A common 45L backpack is typically around 22” D × 14” L × 9” W, though exact dimensions vary by brand.
Backpack Sizes We Use on Our Tours
For most of our hikes, we recommend a 20–45L backpack. Yes — even for our longest treks.
Why? On multi-day hikes like the Laugavegur Trek, we use support vehicles to transport heavier items between lodging locations. This allows hikers to carry only what they need during the day, making a 45L backpack more than sufficient.
For lighter tours or single-day hikes, a 20-22L day pack is usually enough. These smaller packs are ideal when you only need water, snacks, and extra layers.
When traveling to your destination, we always recommend packing as light as possible. A 45L backpack is generally the maximum carry-on size allowed by most U.S. airlines. For international or budget airlines, a pack under 40L is often safer.
Backpack Size Examples (What Each Size Is Best For)
20L – Day pack; water, food, extra layers; carry-on friendly
30L – Travel-focused; works well unless you’re in cold climates
40L – Ideal for travelers and many mountaineers
45–48L – Very popular; largest recommended travel backpack
55L – More than most travelers need unless on technical trips
70L – Often frustrating; larger than necessary for most women
This breakdown helps answer one of the most common questions we hear: is a 45L backpack big enough for hiking? For our tours, the answer is almost always yes.
Women’s HIking Backpack 45L
Fit Matters: Choosing the Right Backpack for Your Body
No matter the size, fit is critical. We strongly recommend:
- No messenger bags
- Always use a waist strap
- Proper weight distribution reduces pressure on your shoulders and back and helps prevent blisters and discomfort.
- To find the right women’s hiking backpack fit, you’ll need your torso length, which is different from height.
How to Measure Torso Length
Find the bony bump at the base of your neck (C7 vertebra)
Locate the top of your hip bones (iliac crest)
Measure the distance between these two points
This measurement helps determine the correct pack size for your body. Most standard hip belts fit waist sizes from the mid-20s to about 40 inches. Women with narrower waists may need a smaller belt or women-specific pack design.
How to Measure your back for a Hiking Backpack (Geekprepper.com)
Conclusion: Choosing the Best Backpack Size for Women
We hope this guide clarifies what does a 45L backpack mean and how to choose the best backpack size for women based on comfort, activity level, and travel style.
Having the right women’s hiking backpack — one that fits your body and matches the trip — makes a huge difference in your experience. Our packing lists are designed to remove guesswork and help you feel confident and prepared.
Looking for your next hiking Edventure? Check out our Women’s Hiking Tours HERE
Some data adapted from: https://geekprepper.com/backpack-sizes-cubic-inches-vs-liters/