The fastest way: measure the diagonal distance across your screen

The screen size of a laptop is the diagonal measurement in inches from one corner of the display to the opposite corner. You do not need to open any menus or settings — you can find this number with a ruler or measuring tape and basic math.

Place a ruler or measuring tape at the bottom left corner of your screen (not including the black border or bezel) and measure diagonally to the top right corner. Write down that number in inches. That measurement is your screen size. Most laptop screens fall between 11 and 17 inches.

This method works even if your laptop is broken or will not turn on. It is also the most reliable way to verify what the manufacturer claims, since some older or refurbished laptops may have incorrect information in their system settings.

Key Takeaways

  • Measure diagonally across your screen with a ruler to find the size in inches — this works whether your laptop is on or off.
  • Windows laptops show screen size in Settings under Display, though the information may not always be accurate for older machines.
  • Mac laptops display screen size in the Apple menu under About This Mac, listed as the model name (like "MacBook Pro 13-inch").
  • Your original purchase receipt or the laptop's bottom panel often lists the screen size if you cannot measure or access system settings.

Finding screen size in Windows Settings

If you have a Windows laptop that turns on, you can check the screen size through the Display settings. Click the Windows Start button in the bottom left corner, then type "Display settings" into the search box and press Enter.

In the Display settings window, scroll down to the "Scale and layout" section. Look for a line that says "Display information" — this section sometimes shows the screen diagonal in inches. However, this information is not always present or accurate, especially on older laptops or machines that have had their display replaced.

If you do not see the screen size listed there, your best option is to measure the screen yourself or check your original purchase paperwork.

Finding screen size on a Mac

Mac laptops make this straightforward. Click the Apple menu in the top left corner and select "About This Mac." The window that opens will show your model name at the top — for example, "MacBook Pro 13-inch" or "MacBook Air 15-inch." The number in the model name is your screen size.

If you see only "MacBook Pro" without a size listed, your laptop is older. In that case, measure the screen diagonally or check your original purchase receipt.

Checking your laptop's physical labels and documentation

The screen size is often printed on a label on the bottom of your laptop or inside the battery compartment. Flip your laptop over and look for a sticker with model and specification information. The screen size may be listed as "Display," "Screen," or "LCD" followed by a number and the inch symbol (").

Your original purchase receipt, invoice, or the box your laptop came in will also list the screen size. If you bought the laptop from a retailer, you can contact them with your order number and they can confirm the specifications.

Why screen size matters when buying replacements

Knowing your screen size is important if you need to buy a replacement display, a protective case, or an external monitor that matches your workspace. Screen size also affects what resolution (sharpness) your laptop can display — a 13-inch screen typically runs at 1920 by 1200 pixels, while a 17-inch screen often runs at 1920 by 1080 or higher.

If you are shopping for a new laptop and want something similar to what you have, the screen size is one of the first specifications to compare. Larger screens are easier to read but make laptops heavier and bulkier; smaller screens are more portable but can feel cramped for long work sessions.

What to do if your screen size is not listed anywhere

If you cannot find the information in settings, on physical labels, or in your paperwork, measuring the screen yourself remains your most reliable option. You will need only a ruler or measuring tape and about one minute.

If you are working with a very old laptop and the display has been replaced, the original screen size may not match what is currently installed. In that case, measure what you have now — that is the size that matters for buying cases, external monitors, or replacement parts.

Frequently Asked Questions

Does screen size include the black border around the display?

No. Measure only the actual lit area of the screen, not the plastic or metal frame around it. Start at the corner where the image begins and end where it stops.

What if my laptop screen is cracked — can I still find the size?

Yes. You can still measure the diagonal of the lit area, check the system settings, or look at the label on the bottom of the laptop. A cracked screen does not change the size measurement.

Is the screen size the same as the resolution?

No. Screen size is the physical diagonal measurement in inches. Resolution is how many pixels fit on that screen — for example, 1920 by 1080. A 15-inch screen can have different resolutions depending on the laptop model.

Can I find screen size information online if I know my laptop model?

Yes. Search your laptop model number (usually found on the bottom sticker or in About This Mac) plus the word "specifications" on the manufacturer's website. Dell, HP, Lenovo, Apple, and other makers list screen size in their spec sheets.

Why does my Windows settings not show screen size?

Older Windows laptops and some custom builds do not include screen size in the Display settings. Measuring the screen or checking the bottom label are more reliable methods for these machines.