The quickest way to find your screen size

The easiest method is to measure diagonally across your screen from one corner to the opposite corner using a tape measure or ruler. Measure from the outer edge of the screen glass itself, not the bezel or frame around it. This diagonal measurement in inches is your screen size — a 24-inch monitor means the screen measures 24 inches corner to corner.

If you do not have a measuring tool handy, check the original box your monitor came in or the documentation that shipped with it. The screen size is always printed on the packaging and in the manual. For laptops, the size is usually printed on a sticker on the bottom or inside the battery compartment.

You can also find the screen size through your computer's settings or by looking up your specific model number online. The method depends on whether you have a desktop monitor or a laptop.

Key Takeaways

  • Measure diagonally across the screen glass from corner to corner with a tape measure to find the exact size in inches.
  • Check the original box, manual, or sticker on your device — the screen size is always printed there.
  • For Windows computers, open Settings and navigate to Display to see the screen resolution and sometimes the size.
  • For Mac computers, click the Apple menu, select About This Mac, and look under Displays to find screen specifications.
  • Your monitor's model number can be looked up online to find the exact screen size and other specifications.

Finding screen size on a Windows desktop

Right-click on your desktop and select Display settings. Scroll down to the Display section. You will see the resolution listed (such as 1920 x 1080), but Windows does not always show the physical screen size here. However, the resolution combined with your monitor model number can help you find the size online.

To find your monitor model number, look at the back or bottom of the monitor for a label with the manufacturer name and model. Search that model number on the manufacturer's website — Dell, LG, ASUS, HP, and others all list screen sizes on their product pages. You can also search the model number on Google to find the specifications sheet.

If your monitor has an on-screen menu, you can sometimes find the model and size information there. Press the menu button on the monitor itself (usually on the bottom edge) and look for an Information or About section.

Finding screen size on a Mac

Click the Apple menu in the top-left corner and select About This Mac. Click the Displays tab. The screen size appears in the window — it will show something like "27-inch (2560 x 1440 Retina)" or similar. This is your screen size in inches.

For MacBook laptops, the same process applies. Go to Apple menu > About This Mac > Displays, and the screen size will be listed. MacBook sizes are typically 13 inches, 14 inches, 15 inches, or 16 inches measured diagonally.

Finding screen size on a laptop

Laptop screen sizes are usually printed on a sticker on the bottom of the device or inside the battery compartment if the battery is removable. Common laptop sizes are 13 inches, 14 inches, 15 inches, 15.6 inches, 17 inches, and 17.3 inches. The sticker will show the exact size.

You can also check your laptop's manual or the original box. If you have lost both, search your laptop's exact model number online — the manufacturer's website will list the screen size in the specifications. The model number is usually on a sticker on the bottom of the device or in the system settings.

Understanding screen size measurements

Screen size is always measured diagonally in inches, not by width or height alone. A 24-inch monitor is 24 inches from the bottom-left corner to the top-right corner (or any opposite corners). This is the standard measurement used worldwide by all manufacturers.

The actual width and height of the screen depend on the aspect ratio — the proportion of width to height. A 24-inch monitor with a 16:9 aspect ratio (widescreen) will be roughly 21 inches wide and 12 inches tall. A 24-inch monitor with a 4:3 aspect ratio (older standard) will be roughly 19 inches wide and 14 inches tall. The diagonal measurement stays 24 inches in both cases.

If you need the measurement in centimeters instead of inches, multiply the inch measurement by 2.54. A 24-inch screen is approximately 61 centimeters.

What to do if you cannot find the model number

If the sticker or label on your monitor is worn away or missing, take a photo of the back and sides of the monitor and post it to a tech forum or subreddit like r/techsupport. Include any visible text, logos, or port types. Other users can often identify the monitor from the design and help you find the specifications.

You can also measure the screen yourself. Measure from the outer edge of the screen glass diagonally to the opposite corner. Round to the nearest whole number or half-inch — most monitors come in standard sizes like 21.5, 24, 27, 32, or 34 inches, so your measurement should land close to one of these.

Why you might need to know your screen size

Knowing your screen size matters when you are buying a replacement monitor, choosing a desk or monitor arm, ordering a screen protector or privacy filter, or troubleshooting display problems. It also helps when you are comparing monitors for work or gaming, since screen size affects how much space you have to work with and how far you need to sit from the screen.

Screen size is different from resolution (the number of pixels). A 24-inch monitor might have 1920 x 1080 resolution or 2560 x 1440 resolution — the screen size stays 24 inches either way, but the higher resolution packs more pixels into the same space, making text and images sharper.

Frequently Asked Questions

Is screen size the same as resolution?

No. Screen size is the physical diagonal measurement in inches — a 24-inch monitor is 24 inches corner to corner. Resolution is the number of pixels, like 1920 x 1080. Two monitors can be the same size but have different resolutions, or the same resolution but different sizes.

Can I measure my screen with my phone instead of a tape measure?

Yes. Use a ruler app on your phone or measure with your phone's camera by placing a known object (like a credit card, which is 3.375 inches wide) next to the screen and comparing sizes in the photo. Measure from the outer edge of the screen glass, not the frame.

What if my monitor is curved or has rounded corners?

Measure the diagonal of the screen glass itself, not the curve or frame. Start at the outer edge of the glass at one corner and measure to the outer edge of the glass at the opposite corner. The curve does not change the diagonal measurement of the screen area.

Do all 24-inch monitors have the same width and height?

No. Monitors with different aspect ratios (like 16:9 versus 16:10) will have different widths and heights even though the diagonal is the same. The diagonal measurement is always 24 inches, but a 16:9 monitor will be wider and shorter than a 16:10 monitor of the same size.

Where is the model number on my monitor if I cannot find a sticker?

Check the back of the monitor, the bottom edge, the sides, and inside the stand if it is removable. Some monitors print the model number on the front bezel in small text. If it is not visible, take a photo of all sides and search for the monitor online using any visible logos or design features.