You asked your laptop “what size is this screen” and Display settings answered with 1920 × 1080. That is resolution, not size. Inches never appear in that menu on most PCs.
Screen size is the diagonal of the viewable panel in inches. Here is how to check it on a phone, laptop, or monitor: online first, then model lookup, then a tape when you need the number to be exact.
What you are checking (size vs resolution)
Screen size: physical diagonal, for example 6.1", 14", or 27".
Resolution: pixel grid, for example 2556 × 1179 or 2560 × 1440.
Viewport: CSS layout width in the browser, not the marketing diagonal.
If support asked for “screen size” and you send pixels, someone will buy the wrong case, arm, or protector. If a designer asked for viewport width and you send inches, the media query will be wrong.
Related guides:
- Measure with a tape: how to measure monitor size
- Read pixels: what is my screen resolution
- Phone bands for layout: mobile screen sizes
Fastest way: check screen size online
Open the free screen size tool on the homepage. It reads what the browser can see and estimates diagonal size from resolution when the exact panel is not uniquely identifiable.
Use the online check when you want a quick answer for:
- “About how many inches is this?”
- A support form that wants a size ballpark
- Confirming you are on a laptop-class vs phone-class display
Limitation: browsers do not expose a reliable “diagonal inches” API. Online tools estimate physical size. For buying a monitor arm, desk, or screen protector, prefer the manufacturer spec or a tape. Monitor-specific estimate: Monitor Size Checker.
How to check screen size on a phone
Phones almost never show “6.1 inches” in Settings the way a product box does.
Option A: online on the phone
Open the screen size checker in Safari or Chrome. You get an instant readout without digging through menus.
Option B: model lookup (most accurate without a tape)
- Find the model: Settings → About / About phone, or the fine print on the SIM tray / box.
- Search the manufacturer page or our device database for that model’s diagonal.
- Examples: iPhone 17 is 6.3", Galaxy S25 is 6.2", Galaxy S25 Ultra is 6.9".
Option C: measure
Same rule as monitors: diagonal of the lit glass only, not the frame. Phone bezels are thin, so a soft tape or a ruler across opposite corners works if you are careful.
For how large phones cluster in 2026, see mobile screen sizes. Series indexes: iPhone, Galaxy S, Pixel.
How to check screen size on a laptop
Windows and macOS Display settings show resolution and scaling. They do not reliably show diagonal inches.
Option A: model sticker or About This Mac / System Information
- Read the model name (MacBook Air 13-inch M4, ThinkPad T14 Gen 5, XPS 14, and so on).
- Look up the product page. The diagonal is almost always in the marketing name or the display section of the spec sheet.
- Browse MacBook, ThinkPad, or the Dell / Apple indexes when you already know the line.
Option B: online estimate
Use the homepage checker or Monitor Size Checker while the laptop is the active display.
Option C: tape
Measure the viewable LCD diagonal only. Common laptop sizes: 13.3", 14", 15.6", 16". Buying guidance: best laptop screen size.
Retina / HiDPI note: a 14-inch MacBook might report a scaled logical resolution in settings while the panel is still a 14-inch diagonal. Do not confuse the scaled pixel mode with physical size.
How to check screen size on a monitor
1. Online checker (fast)
Use the Monitor Size Checker. Good for a quick estimate when you cannot see the back of the panel.
2. Model number (accurate)
- Read the sticker on the back, underside of the stand, or the OSD info menu.
- Search the manufacturer PDF for viewable image size or screen size.
- Cross-check in our monitor database when the model is listed.
3. Tape measure (ground truth)
- Power the display on so the active area is obvious.
- Measure corner to corner on the lit image.
- Skip the bezel.
- Round to the nearest inch.
Full walkthrough with width×height math: how to measure monitor size. Overview companion: what is my monitor size.
Common desktop sizes: 24", 27", 32", ultrawide 34". If you are choosing a second panel, see dual monitor setup size.
How to check screen size on Windows (without inches)
Windows will not give you diagonal inches in Display settings. It will give you the resolution you need for troubleshooting.
- Right-click the desktop → Display settings.
- Note Display resolution (for example 1920 × 1080).
- For inches: use the model lookup, online estimate, or tape methods above.
Changing the pixel mode (not the physical size): change screen resolution on Windows.
How to check screen size on Mac
- System Settings → Displays shows resolution modes and scaled options.
- About This Mac (or System Report → Graphics/Displays) often lists the panel more clearly on Apple hardware.
- For inches on a MacBook, trust the product name (13-inch / 14-inch / 16-inch) or measure the panel. External monitors still need the sticker or a tape.
Changing modes: change screen resolution on Mac.
Which method should you use?
| Goal | Best method |
|---|---|
| Quick answer on any device | Online screen size tool |
| Buy a case, protector, or arm | Model spec or tape |
| Fill a support ticket “screen size” | Inches from model/tape; add resolution separately |
| Responsive design / CSS | Viewport, not diagonal inches |
| Confirm pixels only | Resolution checker |
If you need sharpness (PPI), combine size and resolution in the PPI calculator. That is the next article in this cluster: resolution alone does not tell you if text looks crisp.
FAQ: how to check screen size
- How do I check my screen size quickly?
- Open the screen size checker for an estimate, or look up your device model’s diagonal on the manufacturer page.
- How do I check screen size in inches on Windows?
- Windows Display settings show resolution, not inches. Use the model number, an online estimator, or measure the viewable diagonal with a tape.
- How do I check my phone screen size?
- Check About phone for the model, then look up the diagonal, or open the online checker on the phone. Measuring the glass works if you need a physical confirmation.
- How do I check laptop screen size?
- Read the model name (often includes 13, 14, 15.6, or 16), confirm on the spec sheet, or measure the LCD diagonal. Display settings alone will not show inches.
- Is checking screen size the same as checking resolution?
- No. Size is inches. Resolution is pixels. You often need both: inches for physical fit, pixels for sharpness and GPU load.
Get the inches, then decide what you needed them for
If you wanted a fast number, use the online checker. If you are buying hardware that has to fit, look up the model or measure the viewable diagonal.
Once you have inches, resolution becomes useful: run both through the PPI calculator, or read how to measure monitor size when the online estimate and the box disagree.
Related Articles
Continue reading with these related posts
How to Measure Monitor Size: Diagonal Inches, Bezels, and the Mistakes That Inflate Your Number
Monitor size is the viewable diagonal in inches, not the frame and not your resolution. Measure corner to corner on the lit panel, or calculate from width and height with the Pythagorean theorem.
What Is My Monitor Size? Check It Online or Measure the Diagonal
Your monitor size is the diagonal in inches, not the pixel count. Use our free Monitor Size Checker for an instant estimate, or measure corner to corner with a tape.
What Is My Screen Resolution? How to Check It on Windows, Mac, and in the Browser
Screen resolution is width × height in pixels, not inches. Check it in Display settings, with a free online checker, or via screen.width in the browser. Scaling and DPR can make the number you see differ from the panel's native pixel count.