How to measure your monitor screen size
Monitor screen size is measured diagonally across the glass from one corner to the opposite corner, in inches. A 24-inch monitor means the distance from the bottom-left corner to the top-right corner is 24 inches. This is the standard way manufacturers label monitors, and it is what you will see on the box, in product listings, and in your computer's display settings.
The screen size does not include the plastic bezel (the frame around the glass) or the stand. It measures only the visible display area. This matters because two monitors labeled the same size might look slightly different if one has a thicker bezel, but the actual glass you look at is the same diagonal distance.
You can measure your own monitor with a tape measure or ruler if you want to verify the size. Lay the tape from the bottom-left corner of the screen to the top-right corner, keeping it tight and straight. Round to the nearest inch — manufacturers do the same, so a monitor that measures 23.8 inches is sold as a 24-inch monitor.
Key Takeaways
- Monitor size is the diagonal measurement across the screen in inches, from corner to corner, and does not include the frame or stand.
- You can find your monitor's size on the original box, in Windows or Mac system settings, or by searching the model number online.
- Common monitor sizes range from 21 inches for small office displays to 32 inches or larger for gaming and creative work.
- The same screen size can feel different depending on the resolution — a 27-inch monitor at 1440p looks sharper than a 27-inch monitor at 1080p.
Finding your monitor size in Windows settings
Windows does not display your monitor's diagonal size directly in the main settings menu, but you can find it by looking up your monitor's model number. Right-click on your desktop and select Display settings. Scroll down to the bottom and click Advanced display settings.
Look for the line that says Display and shows your monitor's model name — it might say something like "Dell S2721DGF" or "LG 27UP550". Take that model number and search it on the manufacturer's website or on a search engine. The product page will list the screen size in inches.
If you see only a generic name like "Generic PnP Monitor," the monitor is older or the driver is not installed. In that case, look at the physical monitor itself — many have the size printed on the back or bottom of the stand. If not, measure it yourself with a tape measure.
Finding your monitor size on a Mac
On a Mac, click the Apple menu in the top-left corner and select About This Mac. Click the Displays tab. You will see information about your monitor, but Apple lists resolution and color depth, not the diagonal screen size.
To find the actual size, look for your monitor's model number in the Displays tab — it might say "LG UltraFine 27" or similar. If the size is in the name, you have your answer. If not, take the model number and search the manufacturer's website. You can also check the physical monitor for a label on the back or bottom.
Checking the monitor itself or the original box
The easiest way to find your monitor's size is often the simplest: look at what you have. If you still have the original box, the screen size is printed on the front, back, or side in large text. It will say something like "24-inch" or "27-inch monitor."
If you do not have the box, check the monitor itself. Many manufacturers print the size on a label on the back of the monitor or on the bottom of the stand. You may need to tilt or rotate the monitor slightly to see it. Look for a sticker or printed text that includes a number followed by "inch" or a quotation mark (the symbol for inches).
If there is no label, the model number is usually printed somewhere on the back or bottom. Write down that model number and search it online — the manufacturer's product page will confirm the screen size.
Understanding screen size versus resolution
Screen size and resolution are two different things, and both affect how sharp and detailed your display looks. Screen size is the physical diagonal measurement in inches. Resolution is the number of pixels (tiny dots) that make up the image — something like 1920 × 1080 or 2560 × 1440.
A 27-inch monitor at 1080p resolution will look less sharp than a 27-inch monitor at 1440p, because the same number of pixels is spread across a larger screen in the first case. This is why gaming monitors and creative work monitors often use higher resolutions — they pack more pixels into the same physical size, making text and images clearer.
When you are choosing a monitor, knowing both the size and the resolution helps you understand what you are getting. A 24-inch 1080p monitor is common for office work. A 27-inch 1440p monitor is popular for gaming and photo editing. A 32-inch 4K monitor (3840 × 2160) is used for video work and detailed design.
Common monitor sizes and what they are used for
Monitor sizes range from small to very large, and different sizes suit different tasks. A 21-inch or 22-inch monitor is small and takes up little desk space — it is common in offices where space is tight or for secondary displays. A 24-inch monitor is the standard for most office work, gaming, and general use. It is large enough to see detail without taking up too much room.
A 27-inch monitor is popular for gaming, photo editing, and video work because it gives you more screen space to see detail. A 32-inch monitor is large and is often used for creative professionals who need to see a lot of detail at once, or for people who sit far from their desk. Monitors larger than 32 inches are less common for desktop use because they are hard to see all at once if you are sitting close to them.
Ultrawide monitors (like 34-inch or 49-inch models) are measured the same way — diagonally — but they are much wider than they are tall. These are used for specific tasks like video editing, programming with multiple windows, or gaming in immersive formats.
Why manufacturers measure diagonally
Manufacturers measure monitors diagonally because it is a single number that describes the overall size of the screen, regardless of whether the monitor is wider or taller. A 24-inch monitor could be a standard rectangle (16:9 aspect ratio), a slightly taller rectangle (16:10), or even a square-ish shape — the diagonal measurement stays the same.
This standard has been used since the days of television and has stuck around because it is straightforward and consistent. It does not tell you the exact width or height, but it gives you a quick way to compare monitors and understand roughly how much screen space you are getting.
Frequently Asked Questions
Does the bezel size affect the screen size measurement?
No. The screen size measures only the glass display area, not the plastic frame around it. Two monitors with the same diagonal measurement will have the same size glass, even if one has a thicker bezel. The bezel affects how much desk space the monitor takes up, but not the screen size itself.
Is a 24-inch monitor the same size as a 24-inch TV?
Yes, the diagonal measurement is the same — 24 inches. However, monitors and TVs often have different aspect ratios and resolutions. Most monitors are 16:9 or 16:10, while some TVs are 16:9. A 24-inch monitor and a 24-inch TV will have the same diagonal, but the monitor might be designed for closer viewing and sharper text.
Can I use the resolution to figure out the screen size?
No. Resolution alone does not tell you the screen size. A 1920 × 1080 resolution can be on a 24-inch monitor, a 27-inch monitor, or even a 32-inch monitor. The same resolution on a larger screen will look less sharp because the pixels are spread out more. You need to know both the size and the resolution to understand the display quality.
What if my monitor does not have a label with the size on it?
Search for your monitor's model number online — it is usually on the back or bottom of the monitor. The manufacturer's product page will list the screen size. If you cannot find the model number, you can measure the diagonal distance across the screen with a tape measure and round to the nearest inch.
Does the stand height count toward the screen size?
No. The screen size measures only the diagonal of the glass display itself. The stand, base, and any adjustable arm do not count. This is why two monitors with the same screen size can have different overall heights if one has a taller stand.