The quickest way: measure the diagonal distance across your screen

The screen size of a laptop is the measurement in inches from one corner of the display to the opposite corner, measured diagonally. You can find this yourself with a ruler or measuring tape in about 30 seconds. Measure from the bottom-left corner of the actual screen (not the bezel or frame around it) to the top-right corner. Most laptops fall between 13 and 17 inches.

This method works even if you have lost the original documentation or the label has worn away. The measurement you get is the true diagonal — the number manufacturers use when they list screen size. If your ruler shows 15.6 inches, that is your screen size.

Key Takeaways

  • Measure diagonally across the actual screen glass from corner to corner with a ruler to find your exact screen size in inches.
  • Check the original box, receipt, or product manual if you still have them — the screen size is always listed there.
  • Open your system information through Settings or System Preferences to find the screen resolution, which can help narrow down the size if you measure and get an in-between number.
  • Common laptop sizes are 13, 14, 15.6, and 17 inches — if your measurement falls between two of these, round to the nearest standard size.
  • The screen size does not include the plastic frame or bezel; measure only the glass or display surface itself.

Check your original documentation and product labels

If you still have the box your laptop came in, the screen size is printed on the outside and inside. Look for a label that says "Display" or "Screen" followed by a number and the word "inches" or just the symbol ". The receipt or invoice from where you bought it will also list the screen size in the product specifications.

Many laptops have a small label on the bottom or back of the screen bezel that includes the model number and sometimes the screen size. This label is often hard to read without good light, but it is worth checking if you have the laptop in front of you. The product manual, if you kept it, has the screen size on the first page or in the specifications section.

Look up your laptop model in your system settings

On Windows, open Settings, go to System, then About. Look for "Device name" — this is usually your laptop model. Search that model name online along with the word "specifications" and the manufacturer's website will show you the exact screen size. You can also right-click on the desktop, select Display Settings, and scroll down to see the resolution (like 1920 x 1080), which can help confirm the size once you have the model number.

On Mac, click the Apple menu, select About This Mac, and note the model name and year. Then search "[Model name] specifications" on Apple's support site or your retailer's site. The screen size is always listed in the display specifications section. This method takes a bit longer than measuring, but it gives you the official manufacturer size without any guesswork.

Why screen size matters when comparing laptops

Screen size affects how much space you have to work with and how portable the laptop is. A 13-inch screen is lighter and fits in a small bag, but text and windows are smaller. A 17-inch screen gives you more room to see spreadsheets or video editing timelines side by side, but the laptop weighs more and takes up more desk space. Knowing your current screen size helps you decide whether to stay with the same size or try something different when you upgrade.

Screen size also connects to resolution — the number of pixels displayed. A 15.6-inch laptop typically has a 1920 x 1080 resolution, while a 13-inch might have the same resolution (making text sharper) or a lower one (making everything larger). Understanding your current setup helps you choose a replacement that matches how you actually work.

Common laptop screen sizes and what they are used for

13-inch screens are standard on ultraportable laptops and MacBook Air models. They are light enough to carry daily and fit in most bags. 14-inch and 15.6-inch screens are the most common sizes for general-purpose laptops — they balance screen space with portability. 17-inch screens are found on larger laptops meant for desktop replacement, video editing, or gaming, and they are heavier and less portable.

If you are replacing your current laptop, your screen size is a good starting point. If you spend most of your time at a desk and do detailed work like photo editing or coding, a larger screen might be worth the extra weight. If you travel frequently or move between locations, staying with a smaller size or going smaller usually makes sense.

What to do if your measurement does not match a standard size

Laptop screens come in standard sizes: 13, 14, 15.6, and 17 inches. If you measure and get 15.4 inches, you have a 15.6-inch screen — manufacturers round to the nearest half-inch. If you get 13.3 inches, that is a 13-inch screen. The small difference comes from how the measurement is taken and the thickness of the bezel, but the official size is always one of the standard numbers.

If you are unsure after measuring, use your model number to confirm. Search "[Your laptop model] screen size" and the manufacturer's specification sheet will show the exact official size. This removes any doubt and gives you the number you need if you are shopping for a replacement or looking up compatible accessories.

Frequently Asked Questions

Do I measure the screen including the black border around it?

No. Measure only the glass or display surface itself, from the corner of the actual picture area to the opposite corner. The plastic frame or bezel around the screen does not count toward the size. This is why the official measurement is always slightly smaller than the distance from the outer edge of the laptop frame.

Is screen size the same as resolution?

No. Screen size is the physical diagonal measurement in inches. Resolution is the number of pixels, like 1920 x 1080. A 15.6-inch screen can have different resolutions. Size and resolution are separate specs, and you need both to understand how sharp and spacious your display is.

Can I use my phone to measure the screen?

Yes, if your phone has a built-in measuring app. On newer iPhones, the Measure app can estimate distances. On Android, Google Measure works the same way. Point the camera at the screen corners and let the app calculate the diagonal. A physical ruler or measuring tape is more accurate, but a phone app works in a pinch.

What if I have a laptop with a removable screen?

Some older or specialized laptops have detachable screens. The screen size is still measured the same way — diagonally across the display surface. If the screen is detached, measure it separately. The size does not change whether the screen is attached or removed.

Does the screen size affect how fast my laptop runs?

No. Screen size is purely about the physical display. It does not affect processor speed, memory, or performance. A larger screen may use slightly more power, but the difference is minimal. Performance depends on the processor, RAM, and storage — not on how big the display is.