Where Can I Find The Size Of My Laptop Screen? | Quick Steps

Guide / By

Laptop screen size appears in system info or specs, or by measuring the active diagonal in inches.

Need the actual diagonal in inches? You can read it from the model’s specs, pull it from system data, or take a quick tape measure to the lit area only. This guide gives fast checks for Windows, macOS, and ChromeOS, plus a reliable way to read EDID data when the label is missing.

Find Your Laptop Screen Size: Quick Checks

Start with the options that take under a minute. Pick the one you can do right now, then confirm with a second method if you plan to buy a case, screen protector, or replacement panel.

Check The Model Name And Spec Page

Flip the laptop over or open System info to get the full model code. Search that exact code on the maker’s site. The spec page usually lists the diagonal and panel type. This is the fastest route when you have internet access.

Measure The Lit Area Diagonally

Power the laptop on. Place a ruler or tape from the inner edge of one corner of the display area to the opposite inner corner. Do not include bezels. Round to the nearest tenth of an inch. That value is the marketed size.

Use System Tools To Read EDID

Most displays expose physical width and height (in centimeters) via EDID. On Windows and macOS you can read those fields and compute the diagonal in inches. This skips guesswork when the spec page is vague.

Windows: Fast Ways To Confirm The Diagonal

Grab The Label, Then Verify

Press Win + Pause or open Settings > System > About to note the exact model string. Search the maker’s support page for that model. Cross-check the listed diagonal with what you see on screen.

Read EDID With PowerShell

Windows stores EDID values for connected panels. Run the commands below to fetch width and height in centimeters and convert them to inches. You’ll get a precise diagonal for the active panel.

# PowerShell (run as standard user)
$edid = Get-WmiObject -Namespace root\wmi -Class WmiMonitorBasicDisplayParams |
  Select-Object MaxHorizontalImageSize, MaxVerticalImageSize | Select -First 1
$w = [double]$edid.MaxHorizontalImageSize
$h = [double]$edid.MaxVerticalImageSize
$diag_cm = [math]::Sqrt($w*$w + $h*$h)
$diag_in = $diag_cm / 2.54
"{0:N1} inches" -f $diag_in

Those fields come from the EDID “Basic Display Parameters” block. On some older or odd panels the values may be zero or missing; in that case use the spec page or a tape measure.

macOS: Where To Look

About This Mac > Displays

Go to Apple menu > System Settings > Displays. The panel entry lists the built-in display, resolution, and scaling. For detailed hardware data, open Apple menu > About This Mac > More Info > System Report > Graphics/Displays.

Read EDID From Terminal

If you need the physical diagonal, you can fetch the EDID block and derive width and height. Here’s a quick command that pulls the display record and decodes the size values.

# macOS Terminal
ioreg -l | grep IODisplayEDID | sed -n 's/.*<\(.*\)>.*/\1/p' | xxd -r -p | hexdump -C | head

Use an EDID decoder to read the Max Image Size fields (cm). Convert to inches with the same formula used above.

ChromeOS And Other Systems

Model Code Tells The Story

On many Chromebooks, the sticker on the bottom shows a model like “C434” or “14-dk0xxx,” which maps to a known diagonal. Open Settings > About ChromeOS to copy the exact model string, then check the maker’s page for the screen size listed.

EDID Readers

Some ChromeOS builds expose EDID through crosh or system logs, but this varies. When in doubt, the spec page and a quick diagonal measurement are the two reliable paths.

What Screen Size Really Means

Diagonal Of The Active Area

The published size is the diagonal of the viewable rectangle, not the lid, bezel, or the whole chassis. Two laptops can both be “14-inch” while having very different bezels.

Aspect Ratio Matters For Fit

At the same diagonal, a 16:10 panel is a bit taller than a 16:9 panel. If you’re ordering a sleeve or privacy filter, match both the diagonal and the aspect ratio for a proper fit.

Resolution Isn’t Size

Resolution tells you how many pixels, not the physical inches. A 1920×1080 panel can be 13.3, 14, 15.6, or any size. The diagonal and pixels per inch together define how dense text appears.

Trusted Places To Confirm Specs

When you need a source you can cite on a repair ticket or return, stick to official spec pages or system classes that expose EDID. On Windows, the WmiMonitorBasicDisplayParams class maps to the EDID fields for physical width and height. On Mac, Apple’s System Information page shows where to pull hardware details, including display entries.

Measure Once, Buy Once

When You’re Ordering A Case Or Film

Retail listings often group products by diagonal only, but the cut can be off if the panel is 16:10 or has rounded corners. Check for model-specific accessories when you can. If it’s a generic item, confirm both inches and aspect ratio.

When You’re Replacing A Panel

Replacement screens are sold by diagonal, connector, resolution, refresh rate, and mounting points. Bring the full model code and the panel code (from the part sticker) to get a match. Size alone won’t guarantee fit.

When Specs Don’t Match What You See

If a spec page lists a size that looks wrong, verify with an EDID read and a tape measure. Rare firmware bugs write zeros into the size fields. A second check saves returns.

Formula And Handy Conversions

From Width/Height (cm) To Inches

You can compute the diagonal from EDID width and height values. Use this short formula.

# Given width_cm and height_cm
diagonal_in = sqrt(width_cm^2 + height_cm^2) / 2.54

Typical Laptop Diagonals

Common marketed sizes include 11.6, 12.5, 13.3, 14.0, 15.6, and 16.0 inches. Business models often use 16:10 now, which changes height for the same diagonal.

Troubleshooting Odd Results

EDID Shows 0 cm

Some panels report zeros for physical size. Fall back to the maker’s spec page or measure the lit area.

Multiple Displays Listed

If your script returns more than one entry, pick the record with the active output or the one that lists non-zero sizes. Laptops with hybrid graphics can expose two paths.

Spec Page Uses Marketing Names

Terms like “Retina,” “Liquid Retina,” or “InfinityEdge” describe pixel density or bezel style, not the diagonal. Find the number that ends with inches.

Quick Table: Methods, Where, And Accuracy

Method Where You’ll Find It Accuracy
Model Spec Page Maker’s support page for your exact model code High
Measure Lit Diagonal Tape across active area, corner to opposite corner High
Read EDID Fields Windows PowerShell or macOS System Report/Terminal High when values exist
Retail Listing Guess Third-party store page matching the model family Medium
Model Name Pattern Sticker like “14-xxx” implies a rough diagonal Medium

Step-By-Step: Verify Size On Popular Brands

HP, Dell, Lenovo

Copy the full model string from System info or the bottom sticker. Paste it into the brand’s support site search box. Open the product specifications page and look for “Display” or “Panel.” You’ll see the diagonal next to the panel type.

Apple MacBooks

Open System Settings > General > About > System Report > Graphics/Displays. Note the built-in panel name and resolution. The product page for your model on Apple’s site also lists the diagonal for that exact release year.

Acer, ASUS, Samsung, Microsoft

Use the model code path first, then confirm with EDID when possible. Many makers reuse model families across sizes; only the full code nails the diagonal.

Checklist Before You Buy Accessories

  • Confirm the diagonal in inches using two methods.
  • Match the aspect ratio (16:9, 16:10, 3:2) for sleeves and filters.
  • Note the webcam location and notch shape for screen protectors.
  • If buying a replacement panel, match connector, resolution, and refresh rate.
  • Save a screenshot of the spec page next to your order for easy returns.
  • If you only have centimeters, divide by 2.54 to get inches.
  • Snap a photo of your diagonal measurement to match store listings later.

EDID Accuracy And Limits

Why Numbers May Be Missing

Some panels ship with empty size fields in EDID. In that case, your script returns zeros. That is not a fault with your laptop. Use the maker’s spec page or a tape measure for the final number.

Docking Quirks

If you test while using a dock or HDMI adapter, EDID can come from the adapter. Unplug extras, run the script on the built-in panel, and try again.

Accessories: Match More Than Inches

Privacy Filters And Films

Filters and films are cut to aspect ratio and active width/height. A filter made for 16:10 will not align on a 16:9 panel even when the diagonal matches. Compare the listing’s millimeter dimensions to your measured lit area.

Sleeves And Bags

Sleeves list interior width and depth. Measure the closed laptop’s footprint, not the diagonal, and leave a few millimeters for the zipper and padding.