How to Check the Screen Size of Your Laptop
Knowing your laptop's screen size matters more than you might think. Whether you're shopping for a replacement screen, buying a laptop bag, connecting an external monitor, or comparing models, the display size affects everything from portability to how comfortable the machine is to use for long sessions. Here's how to find it — using physical measurement, software tools, or your laptop's documentation.
What "Screen Size" Actually Means
Laptop screen size is measured diagonally — from the bottom-left corner of the display panel to the top-right corner (or vice versa). This measurement does not include the bezel (the plastic or metal border surrounding the screen). It's the active display area only.
Common laptop screen sizes range from 11 inches on compact ultraportables up to 17 or 18 inches on desktop-replacement machines, with 13-inch, 14-inch, and 15.6-inch being the most common categories in consumer laptops.
Method 1: Measure It Physically 📏
The most reliable method when you have the laptop in front of you:
- Open the lid fully.
- Place a measuring tape or ruler at one corner of the screen itself (not the bezel).
- Stretch diagonally to the opposite corner of the screen.
- Read the measurement in inches — that's your screen size.
Tips for accuracy:
- Use a soft measuring tape if you have one; it follows the slight curve of some screens better.
- Make sure you're measuring the visible display panel, not the full lid.
- Round to the nearest standard size (e.g., 15.4 inches is commonly labeled as a 15-inch screen).
Method 2: Check System Settings or Display Info
Your operating system can surface display information, though it won't always give you the diagonal inch measurement directly — it typically shows resolution instead. Here's how to dig further.
On Windows
- Right-click the desktop → Display Settings
- You'll see your resolution (e.g., 1920×1080) and display arrangement.
- For more detail: open Device Manager → expand Monitors → right-click your monitor → Properties. The model name shown here can be searched online to find the exact screen size.
Alternatively, use the System Information tool:
- Press
Windows + R, typemsinfo32, hit Enter - Navigate to Components → Display for display adapter details
On macOS
- Apple menu → About This Mac → Displays
- macOS typically names the display (e.g., "Built-in Retina Display") but won't list diagonal inches here.
- The model identifier shown can be cross-referenced with Apple's tech specs pages to confirm the exact display size.
On Linux
Run the following in terminal:
xrandr | grep " connected" This returns your display's resolution and can include physical dimensions in millimeters — divide by 25.4 to convert to inches, then calculate the diagonal using basic geometry if needed.
Method 3: Use Your Laptop's Model Number 🔍
Every laptop has a model number, and that's often the fastest route to confirmed specs.
Where to find the model number:
- On a sticker on the bottom of the laptop
- In System Settings → About (Windows) or About This Mac (macOS)
- On the original box or receipt
Once you have the model number, search it directly on the manufacturer's website (Dell, HP, Lenovo, Apple, ASUS, etc.) or enter it into a search engine with the word "specs." The official spec sheet will list the display size, resolution, panel type, and refresh rate.
Method 4: Check Third-Party System Info Tools
Tools like CPU-Z, Speccy (Windows), or HWiNFO pull detailed hardware information from your system. Some will display monitor information including the model number of your display panel, which you can then look up for the diagonal measurement.
These tools are particularly useful when the sticker on the bottom is worn off or the model isn't immediately obvious from system settings.
Why Screen Size Measurements Can Be Confusing
| Labeled Size | Actual Measured Size | Notes |
|---|---|---|
| 15.6" | ~15.6" | Most consistent |
| 13.3" | ~13.3" | Common ultrabook size |
| 15" | 15.0–15.4" | Older models vary |
| 14" | ~14.0" | Growing category |
| 17.3" | ~17.3" | Desktop-replacement class |
Manufacturers have generally standardized around consistent measurements, but older laptops — particularly those made before 2010 — sometimes show more variation between the labeled size and actual measured diagonal. If you're ordering a replacement screen or a fitted case for an older machine, always measure physically rather than relying solely on the labeled size.
The Variables That Change What You Actually Need to Know
Finding the screen size is straightforward. What's less straightforward is knowing what to do with that number — and that depends heavily on your situation.
For laptop bag shopping: You typically need the screen size but also the overall laptop dimensions (width × depth × height), since two 15.6-inch laptops from different manufacturers can have very different footprints depending on bezel thickness.
For replacement screens: The diagonal size alone isn't enough. You'll also need the resolution, panel type (IPS, TN, OLED), connector type, and whether your model uses a 30-pin or 40-pin eDP connector. Two screens can be the same size but completely incompatible.
For external monitor pairing: Screen size helps you judge relative scale, but resolution and aspect ratio matter just as much for a seamless dual-display experience.
For comparing portability: A 14-inch laptop with a thin bezel can have a smaller overall footprint than a 13-inch model with thick bezels — so screen size and physical size aren't always directly correlated.
The measurement itself takes about 30 seconds. How that number fits into your specific situation — whether you're replacing a part, buying an accessory, or evaluating a new purchase — is where your own setup and needs become the deciding factor.