What Is My Laptop Size? How to Find Your Screen Size Fast

AvatarByEric Dawson Computers & Software

Your laptop size is the diagonal measurement of the screen in inches, taken from one corner of the viewable glass to the opposite corner and ignoring the plastic bezel around it. Most machines sold in the United States fall between 11.6 and 17.3 inches. Neither Windows nor macOS prints that figure in a settings panel, so three practical routes exist: read your model number and look up the official specification, open About This Mac if you use a Mac, or lay a tape measure across the panel. Looking up the model number is almost always fastest, and it gives you the number the manufacturer stands behind.

What Laptop Size Actually Means

Laptop size nearly always refers to the screen diagonal, measured in inches across the viewable display area. Everything outside the glass is excluded: the bezel, the hinge, the lid and the keyboard deck. That convention holds across every major manufacturer, so a panel described as 15.6 inches by HP is measured exactly the same way as one described as 15.6 inches by Dell.

Shoppers sometimes use the word size to mean footprint or weight instead, and those are fair questions when a machine has to fit in a bag. Specification sheets do not work that way. When a listing says 14-inch or 17.3-inch, it is describing the diagonal of the display and nothing else.

Why the Diagonal and Not the Width

One number is easier to shop by than two, though the diagonal does hide some detail. Two panels can share a diagonal and still differ in physical width. LaptopScreen.com points to Toshiba Portege models whose 13.3-inch panels were sold at both 303 millimeters and 306 millimeters wide, a difference that matters enormously if you are buying a replacement part and barely at all if you are buying a sleeve.

Marketing Sizes and Real Diagonals

Rounding is common, and it is not an attempt to mislead anyone. Sony has marketed panels as 15.5 inches that are physically the same 15.6-inch part, according to LaptopScreen.com, and the two screens are interchangeable. Apple rounds in the other direction, shaving a few tenths off in its product names, which the section on Mac laptops below sets out in full.

How to Find Your Laptop Size on Windows

Windows has no setting that displays the physical screen size, so the reliable method is to read your exact model name in System Information and look that model up on the manufacturer’s specification page. Microsoft’s own support answers say the same thing: the operating system reports resolution and scaling, never inches. A lookup takes about a minute and returns the figure the manufacturer certifies.

Using System Information

System Information hands you the model string the manufacturer uses in its own catalog, which is what makes the lookup accurate rather than approximate.

  1. Open the Run box: hold the Windows key and press R.
  2. Start System Information: type msinfo32 and press Enter.
  3. Read System Manufacturer: on the System Summary page, note the maker, such as HP, Dell, Lenovo or ASUS.
  4. Read System Model: the line directly beneath it holds the model string, for example Inspiron 5410 or Pavilion Laptop 15-eh1xxx.
  5. Search the maker’s site: paste that exact string into the support or product search on the manufacturer’s own domain.
  6. Open the specifications: find the display row, which lists the diagonal in inches alongside the resolution and panel type.

Using the Settings App

Settings reaches the same model number with fewer keystrokes, although the entry there is occasionally less specific than the System Information one.

  1. Open Settings: hold the Windows key and press I.
  2. Choose System: it sits at the top of the left-hand list.
  3. Scroll to About: the About page is the last entry in the System group.
  4. Read Device specifications: device name and model number appear together near the top.
  5. Look the model up: search that number on the manufacturer’s site and read the display specification.

Why Windows Shows Resolution Instead of Inches

Resolution is a pixel count, and a pixel count cannot be converted into inches on its own. A 1920 by 1080 panel exists at 13.3 inches, at 15.6 inches and at 17.3 inches, and the operating system has no way to know which one is bolted into your lid. Display settings will happily report resolution and the scaling percentage, and neither figure answers the question you actually asked.

Some laptops give the answer away in the model name itself. HP Pavilion 15, Dell Inspiron 14 and similar names carry the rounded screen size, so the number that follows the family name is usually the diagonal in inches. Treat that as a strong hint rather than proof, because a 15 in the name means a 15.6-inch panel far more often than a 15.0-inch one.

How to Find Your MacBook Screen Size

macOS lists the size for you, which makes a Mac the easiest case of all. Click the Apple menu, choose About This Mac, and the display appears in inches next to its native resolution, shown as something like 13-inch (2560 x 1440). No measuring and no model lookup required.

Checking About This Mac

About This Mac is the fastest check on any Mac laptop, and it takes two clicks from the desktop.

  1. Open the Apple menu: click the Apple logo in the top-left corner of the screen.
  2. Choose About This Mac: the first item in the menu.
  3. Read the display line: the size in inches sits beside the native resolution in parentheses.
  4. Check any extra monitors: every connected display is listed with its own size, so make sure you are reading the built-in one.

Checking System Settings on Newer macOS Versions

Recent macOS releases file the same information under System Settings, which helps when the About This Mac panel has been redesigned out from under you.

  1. Open the Apple menu: click the Apple logo, then choose System Settings.
  2. Select General: it appears in the sidebar on the left.
  3. Click About: the model name and identifier are listed here.
  4. Open Display Settings: the button on this page takes you to the panel that names each display and its size.

Apple’s Sizes at a Glance

Apple names its laptops in round numbers and builds them a little larger. Real diagonals run a few tenths of an inch above the marketing figure, which is why a case cut for a 15-inch laptop is not automatically the right case.

Marketed size Actual diagonal
13-inch 13.6 inches
14-inch 14.2 inches
15-inch 15.3 inches
16-inch 16.2 inches

Those tenths matter most when you buy a fitted sleeve, a screen protector or a privacy filter. For a backpack or a desk stand, the rounded name is close enough.

How to Measure Your Laptop Screen Yourself

Run a tape measure from one bottom corner of the glass to the opposite top corner and read the result in inches. That diagonal is the screen size. Keep the tape on the viewable area and off the bezel, because including the frame is the single most common reason a home measurement comes out too large.

Measuring the Diagonal

Two minutes and a flexible tape measure are all this takes. A rigid ruler works, but it fights you across a diagonal and is easier to misalign.

  1. Turn the laptop on: a lit screen shows precisely where the viewable area stops and the bezel starts.
  2. Pick a corner: anchor the tape at the bottom-left corner of the lit area.
  3. Stretch across: pull the tape to the top-right corner of the lit area, not the corner of the lid.
  4. Keep it flat: a tape that lifts off the glass adds length and skews the reading.
  5. Read the inches: note the figure to one decimal place.
  6. Round to a standard size: match your reading to the nearest common size, so 15.5 means you own a 15.6-inch panel.

Using Width and Height Instead

Rigid rulers sit badly across a diagonal, so measure the width and the height separately and finish the job with the Pythagorean theorem. Square each figure, add the two results, take the square root, and the answer is your diagonal in the same units you started with.

A Worked Example for a 15.6-Inch Screen

Say the viewable area measures 13.6 inches across and 7.6 inches down. Squaring those gives 184.96 and 57.76. Adding them produces 242.72, and the square root of 242.72 is 15.58, which rounds to the standard 15.6-inch panel.

A smaller machine behaves identically. Measure 11.3 inches by 7.1 inches, square both to get 127.69 and 50.41, add them for 178.10, and the square root is 13.34. Round that and you have a 13.3-inch screen.

Converting Millimeters to Inches

Divide the millimeter figure by 25.4 and you have inches. Panel specification sheets and replacement part listings often quote width in millimeters, so this conversion comes up more often than you would expect. A 303 millimeter panel width works out to 11.93 inches, while a 306 millimeter width is 12.05 inches, and that tenth of an inch is exactly the gap LaptopScreen.com describes between two Toshiba Portege panels that both count as 13.3-inch screens.

Which Method to Use, Compared

Looking up the model number beats every other approach on speed and accuracy, and physical measurement is the fallback for when both the paperwork and the model string fail you. Seven realistic options, ranked on what each one actually costs you, appear below.

Method Difficulty Accuracy Speed Equipment needed
Search the model online Easy Very high Fast Internet access
Check original documentation Easy Very high Fast Manual or box
Windows System Information plus lookup Easy Very high Fast The laptop itself
About This Mac Easy Very high Fast A Mac laptop
Physical measurement Medium High Slow Tape measure or ruler
Online tool such as whatsmyscreen.com Easy Medium Very fast Browser and a reference card
Smartphone measuring app Medium Medium Medium Phone with a measuring app

Accuracy in that table means how closely the result lands on the figure the manufacturer publishes. Very high covers the methods that simply read the published number back to you. High and medium cover the methods that estimate it, where your own care with the tape or the reference card decides the outcome.

I would start with the exact model number rather than a tape measure. It gives the screen size the laptop was sold with, while a hurried measurement can catch part of the bezel or land slightly off the display corners. The exception is a MacBook, where About This Mac is the simpler choice because it shows the size directly. I would measure only when the model cannot be identified or when I need to check whether a replacement screen matches the panel already fitted.

Common Laptop Screen Sizes and What They Are For

Standard laptop screens run from 11.6 inches to 17.3 inches on the diagonal. Sizes you will meet most often are 10.1, 11.6, 13.3, 14.0, 15.6 and 17.3 inches, and 15.6 inches is the mainstream default for Windows machines sold in stores.

Screen size Category Typical use Examples
11 to 12 inches Ultraportable Maximum portability 11.6-inch Windows laptops, older netbooks
13 to 14 inches Thin and light Balance of portability and usable screen Dell XPS 13, Apple 13-inch and 14-inch models
15 to 16 inches Standard or mainstream General purpose computing HP Pavilion 15, Apple 15-inch and 16-inch models
17 to 18 inches Desktop replacement Graphics work, heavy productivity, gaming 17.3-inch gaming and workstation laptops

Nothing stops a manufacturer from picking an unusual diagonal, and a handful do, but the clusters above cover the large majority of what is on sale. HP frames the same ground as a trade-off between screen area and how much the machine weighs in a bag, which is the decision most buyers are really making when they pick a size.

Why the Number on the Box Does Not Match Your Tape Measure

Three things explain nearly every mismatch: bezel caught in the measurement, marketing that rounds the figure, or one diagonal covering panels of slightly different widths. None of them means the published specification is wrong.

Bezel is the biggest culprit by some distance. Screen size counts the viewable display area alone, so every millimeter of frame you include pushes the reading up. Modern thin-bezel designs make the boundary harder to see when the machine is switched off, which is why measuring a lit screen is worth the extra few seconds.

How Close Is Close Enough

Round your measurement to the nearest size on the standard list and use that. Reading 15.4 or 15.5 inches means you own a 15.6-inch panel, and reading 13.2 inches means a 13.3-inch one. Nothing on the market sits between those steps, so a result that falls between two standard sizes is a measuring error rather than a discovery.

When the Specification and the Measurement Disagree

Trust the manufacturer’s published specification. It is the number the panel was built to and the number every accessory maker designs around, whereas a tape held across a curved bezel is easy to misread by a tenth of an inch. Re-measure only when your result sits more than half an inch from the published size, since a gap that large usually means you caught some bezel or the machine is not the model you assumed.

If You Still Cannot Confirm Your Laptop Size

Pull the model number off the sticker on the underside of the laptop and search that exact string on the manufacturer’s site. Almost every machine carries one, including refurbished units that arrived with no box and no manual.

Laptops Bought Used or Refurbished

Missing paperwork does not block you, because the model number lives on the machine itself in more than one place. Work through these in order:

  • The service sticker on the bottom panel, which usually carries the model and the serial number.
  • System Information on Windows, reached with the Windows key and R, then msinfo32.
  • About This Mac on a Mac laptop, which names the size directly.
  • A label under the battery or inside the battery bay on older designs with removable batteries.

Sellers of refurbished stock list the model number in the listing as well, so an old order confirmation or marketplace receipt is worth checking before you reach for a screwdriver.

Ordering a Replacement Screen

Never order a replacement panel on the diagonal alone. LaptopScreen.com recommends removing the screen, reading the model number printed on the label on its back, and giving that number to the supplier, because panels that share a 13.3-inch or 15.6-inch label can differ in width, connector and mounting. Two machines from the same family and the same year can take different parts.

Online Tools and Phone Apps

Browser tools and phone apps produce an estimate in seconds, and an estimate is often all you need. The site whatsmyscreen.com asks you to hold a standard card, such as a credit card, flat against the display as a reference object, then works the size out from the comparison. Measuring apps on a phone, including AR ruler tools and Apple’s Measure app, give a diagonal that you then round to the nearest standard size.

Neither shortcut beats a specification sheet for accuracy. Use them when the laptop will not power on, when the stickers have worn away, or when you just want a quick sanity check before ordering an accessory.

Frequently Asked Questions

Can Windows Tell Me My Screen Size in Inches?

No. Windows reports resolution and display scaling rather than physical dimensions, and Microsoft’s own support answers confirm there is no built-in setting that shows inches. Read your model name in System Information and look it up on the manufacturer’s site instead.

Is a 15.6-Inch Laptop the Same as a 15-Inch MacBook?

Not quite, and the gap is wider than the labels suggest. Apple’s 15-inch models measure 15.3 inches on the diagonal, so a 15.6-inch Windows panel is slightly larger. Cases and sleeves are not reliably interchangeable between the two.

Does Screen Resolution Tell You the Screen Size?

It does not. Resolution counts pixels, and the same 1920 by 1080 grid ships on 13.3-inch, 15.6-inch and 17.3-inch panels alike. What resolution does reveal is pixel density, but only once you already know the diagonal.

Should I Include the Bezel When I Measure?

No. Screen size covers the viewable display area only, and the frame around it is excluded by every manufacturer that publishes a specification. Including the bezel is the usual reason a home measurement reads half an inch or more above the advertised size.

What Screen Sizes Do Laptops Come In?

Standard laptop screens run from 11.6 to 17.3 inches, with 10.1 inches at the small end of the market. Sizes you will meet most often are 11.6, 13.3, 14.0, 15.6 and 17.3 inches. Apple works to its own set, marketing 13-inch, 14-inch, 15-inch and 16-inch machines that actually measure 13.6, 14.2, 15.3 and 16.2 inches.

Start with the model number, because it is the one answer that arrives with a manufacturer behind it. System Information on Windows and About This Mac on a Mac both surface it in under a minute, and a search on the maker’s own site turns it into a diagonal in inches. Keep the tape measure for the cases where the machine has no readable sticker and will not switch on, and round whatever you measure to the nearest standard size before you spend money on a sleeve, a privacy filter or a replacement panel.

What This Page Does Not Publish

  • I do not cover Linux-specific screen checks here, so use your distribution’s display tools or measure the panel.
  • I do not settle disagreements between a listed specification and a physical measurement.
  • I focus on common consumer laptops, not specialist or enterprise models.

References

Author Profile

Eric Dawson
Eric Dawson
I'm Eric Dawson, the writer behind The Money Watch. I live in the Columbus, Ohio area and I write about the ordinary questions that turn out to be complicated: computers, shopping, food, travel, parking, small businesses, fees, rules and products. Every article starts with the official page, the maker or the agency, then the sources that check it, and I say plainly where they disagree and what I would do. More about how I work is on the About page.