What Size Laptop Bag Do I Need? A Simple Guide to Measuring Your Laptop Correctly
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Last Updated: November 2025
Choosing a laptop bag becomes much easier once you know your laptop’s real measurements. Manufacturer sizing can be confusing, and bags vary a lot between brands. This guide shows you exactly how to measure your laptop and match it to the right bag size without guesswork.
👉 If you want help choosing a stylish or functional bag afterward, check our guide on best laptop bags & cases.
🔍 Why Bag Size Matters
A properly sized laptop bag protects your device from pressure, bumps, and corner stress. Too tight and it won’t slide in. Too loose and it moves around inside. Getting the right fit makes daily carrying much safer and more comfortable.
🔍 How to Measure Laptop Size for a Bag
That “13-inch,” “14-inch,” or “15.6-inch” label refers only to the screen diagonal, not the actual body. That’s why measuring your laptop yourself is the most accurate approach.
How to Measure Your Laptop
- Measure the diagonal of the screen
- Measure the width (side to side)
- Measure the height/depth (front to back)
- Measure the thickness
Choose a bag that’s slightly larger in each dimension for a comfortable fit.
🔍 Are Laptops Measured Diagonally?
Yes. Laptop sizes are always based on the diagonal screen measurement.
This doesn’t include bezels or frame thickness, which often add extra size you need to account for when choosing a bag.
🔍 Laptop Bag Size Guide (No Table)
13-inch laptops
Typical: ~12.0″ × 8.5″
Recommended bag size: 13–14 inch
14-inch laptops
Typical: ~12.7″ × 9.0″
Recommended bag size: 14–15 inch
15.6-inch laptops
Typical: ~14.1″ × 9.8″
Recommended bag size: 15.6–16 inch
16-inch laptops
Typical: 14.0–14.3″ × 10.0″
Recommended bag size: 16–17 inch
17-inch laptops
Typical: ~15.7″ × 10.7″
Recommended bag size: 17–18 inch
👉 Always check the internal dimensions of the bag—padding thickness affects usable space.
🔍 Special Situations
Large or thick laptops
Gaming and workstation laptops often need one size up because of vents and extra chassis thickness.
Vertical laptop bags
For upright bags, height becomes the most important measurement.
Bags for two laptops
Look for dual-compartment bags with two padded sleeves to prevent devices from rubbing.
🔍 Measuring for Laptop Backpacks
Backpack sleeves tend to be snug. Your laptop’s width and height should fit inside the sleeve’s listed dimensions. If it’s a tight match, size up.
📌 Key Takeaways
- Laptop sizes are based on diagonal screen measurements, not full body size
- Measure your laptop’s width, height, and thickness for accurate bag matching
- Always compare measurements with the bag’s interior dimensions
- Leave 0.5–1 inch of extra room for easy sliding and better protection
- Gaming or large laptops often need a slightly bigger bag
🟢 FAQs
Q: What size laptop bag do I need?
Measure your laptop’s diagonal, width, height, and thickness, then match them to the bag’s internal size.
Q: What size bag fits a 15.6-inch laptop?
Most fit easily in 15.6–16 inch bags.
Q: Do 14-inch laptops always fit 14-inch bags?
Usually, but thicker laptops may need a slightly larger bag.
Q: Can laptop bags be used as personal items on flights?
Yes—most airlines allow them as long as they fit under the seat.
✅ Conclusion
Once you know your laptop’s real measurements, finding the right bag becomes simple. Match the width, height, and thickness to the bag’s internal dimensions, and you’ll have a fit that keeps your device protected and easy to carry every day.
