The quickest way to check your laptop screen size
The easiest method is to measure diagonally across your screen from the bottom-left corner to the top-right corner, using a tape measure or ruler. Measure only the glass or display surface itself, not the black border or bezel around it. That diagonal measurement in inches is your screen size — a laptop with a 15.6-inch screen measures 15.6 inches corner to corner.
If you do not have a measuring tool handy, your laptop's original box or documentation usually lists the screen size. Check the box your laptop came in, the user manual, or any paperwork that arrived with it. The size is almost always printed on the outside of the box in large text.
You can also find the screen size through your operating system settings without opening the box or measuring anything. The steps differ between Windows and Mac, but both take less than a minute.
Key Takeaways
- Measure diagonally across the display surface from corner to corner in inches to find your screen size.
- Your laptop's original box or user manual will list the screen size if you still have that documentation.
- Windows shows screen size in Settings under Display, though you may need to check your device manager or manufacturer's software for the exact diagonal measurement.
- Mac displays screen size in About This Mac under System Report, listed as the native resolution and diagonal size.
- The screen size you find refers to the diagonal measurement only and does not include the plastic border around the display.
Finding screen size in Windows settings
Open Settings by pressing the Windows key and typing "Settings," then select the Settings app. Click on "System" in the left sidebar, then select "Display" from the menu that appears. Scroll down to the "Display" section and look for information about your display resolution and size.
Windows does not always show the diagonal screen size directly in the Display settings. If you see only resolution (like 1920 x 1080) but not the diagonal measurement, you will need to check your device manager or your laptop manufacturer's software. Right-click on the Windows Start button, select "Device Manager," then expand "Monitors" to see if your display model number is listed there.
Once you have the model number, search for it online along with your laptop brand — for example, "Dell Inspiron 15 display model number." The manufacturer's website or the display maker's specifications will show the diagonal screen size. This method takes a few extra steps but gives you the exact measurement without a tape measure.
Finding screen size on a Mac
Click the Apple menu in the top-left corner and select "About This Mac." In the window that opens, click the "System Report" button. Look for "Graphics/Displays" in the left sidebar and click it to expand that section.
Under the display information, you will see a line that says something like "Resolution: 2560 x 1600 (Retina)" followed by the diagonal screen size. On newer Macs, the size appears as "Display" with the measurement in inches — for example, "13.3-inch (diagonal)." This is your screen size.
Understanding what screen size means
Screen size is always measured diagonally in inches, from one corner of the display to the opposite corner. A 15.6-inch laptop screen and a 15.6-inch desktop monitor have the same diagonal measurement, but they may look different because the width-to-height ratio can vary. Some screens are wider (16:9 aspect ratio), while others are taller (3:2 aspect ratio).
The diagonal measurement is the industry standard because it describes the overall display area in a single number. Two laptops with the same screen size may have different widths and heights depending on their aspect ratio, but the corner-to-corner measurement will be the same.
Common laptop screen sizes range from 11 inches on ultraportable models to 17 inches on larger workstations. Most everyday laptops fall between 13 and 15.6 inches. Knowing your exact screen size helps you understand what to expect when shopping for a replacement screen, an external monitor, or a laptop bag that fits properly.
Why manufacturers sometimes list screen size differently
Laptop manufacturers occasionally round screen sizes or use approximate measurements. A screen advertised as "15-inch" might actually measure 15.6 inches diagonally. This rounding is common in marketing materials but should not affect your ability to find the exact measurement through settings or the original documentation.
Some older laptops or budget models may have documentation that lists only the resolution (like 1366 x 768) without the diagonal size. If you have the resolution and model number, you can calculate the diagonal size using online tools or by searching the display manufacturer's specifications. The resolution alone does not tell you the screen size — two displays with the same resolution can have different diagonal measurements.
What to do if you cannot find the original box or documentation
If your laptop's original box is gone and the settings method does not show the diagonal size, a physical measurement is your most reliable option. Use a tape measure or ruler to measure from the bottom-left corner of the display glass to the top-right corner. Round to the nearest tenth of an inch — most laptop screens are manufactured in standard sizes like 11, 13, 13.3, 14, 15, 15.6, or 17 inches.
You can also contact your laptop manufacturer's support team with your laptop's model number. They can confirm the screen size in seconds. Look for the model number on a sticker on the bottom of your laptop or in the Settings app under "System Information" (Windows) or "About This Mac" (Mac).
Frequently Asked Questions
Does screen size include the black border around the display?
No. Screen size measures only the glass or LCD panel itself, from corner to corner of the viewable area. The plastic bezel or border around the display is not included in the measurement. When you measure with a tape measure, measure only the display surface, not the frame.
Is a 15-inch screen the same as a 15.6-inch screen?
They are close but not identical. A 15-inch screen measures 15 inches diagonally, while a 15.6-inch screen measures 15.6 inches. In practice, manufacturers often round or use "15-inch" as shorthand for 15.6-inch in marketing materials. Check your documentation or measure to confirm the exact size.
Can I find screen size by looking at the laptop's model number alone?
Sometimes. Many laptop model numbers include the screen size — for example, "MacBook Air 13" or "Dell XPS 15." However, not all manufacturers follow this pattern, and some older models use codes that do not indicate size. Your best bet is to check the original box, the settings menu, or contact the manufacturer directly with your full model number.
What if Windows shows only resolution and not the diagonal screen size?
Windows Display settings often show resolution but not the diagonal measurement. Find your display's model number in Device Manager under "Monitors," then search online for that model number plus your laptop brand. The manufacturer's specifications will list the diagonal screen size.
Why does my screen size matter when choosing an external monitor?
Knowing your laptop screen size helps you understand what size external monitor will feel comfortable to work with. If you are used to a 15.6-inch laptop screen, a 24-inch external monitor will feel noticeably larger. Screen size also affects how much desk space a monitor needs and how far away you should sit from it.