Screen Size Comparison at Home: Measure Any Display

Shopping for a new phone, TV, or monitor? The screen size is usually the first spec people look at — but most buyers don't realize that a "27-inch" measurement doesn't tell you the full story. Here's how to measure, compare, and understand screen sizes at home so you never buy the wrong size again.

How Screen Size Is Actually Measured

Every screen size — whether it's a 6.1-inch phone or a 65-inch TV — is measured on the diagonal, from one visible corner to the opposite corner. This is the glass area only; the bezel (frame) is not included. Manufacturers have used this standard for decades.

Here's what popular screen sizes translate to in actual width and height (16:9 aspect ratio):

How to Measure a Screen at Home

You only need a tape measure or ruler and two minutes:

1. Turn off the display so you can see the edge of the active area clearly against the bezel.
2. Place the tape at one visible corner of the screen (bottom-left works well).
3. Stretch diagonally to the opposite corner (top-right). Keep the tape taut.
4. Read the measurement in inches. This is your screen's diagonal size.
5. Do not include the bezel. Only the lit/display area counts.

If your tape measure is in centimeters, divide by 2.54 to convert to inches. For example, 68.6 cm ÷ 2.54 = 27 inches.

Diagonal vs Area: Why the Number Lies

The diagonal measurement is convenient but misleading. A 6.9-inch phone screen is only 13% larger diagonally than a 6.1-inch phone, but it has 42% more screen area. That's because area grows with the square of the diagonal — small changes in diagonal create much bigger changes in usable space.

This is why comparing screen areas is more useful than comparing diagonals. For example:

• 6.1″ → 6.7″ phone: +10% diagonal, but +22% more area. Feels noticeably bigger for reading and media.
• 24″ → 27″ monitor: +12.5% diagonal, but +26% more area. That's over a quarter more workspace.
• 55″ → 65″ TV: +18% diagonal, but +40% more area. The jump from 55 to 65 is much bigger than the numbers suggest.

See this in action: compare the iPhone 16 vs iPhone 16 Plus or the Galaxy S25 vs S25 Plus to visualize how much extra screen you actually get.

Aspect Ratio Changes Everything

Two screens with the same diagonal can have different areas if their aspect ratios differ. A 27-inch 16:10 monitor (common on business laptops and some monitors) has about 3.7% more area than a 27-inch 16:9 monitor. Ultrawide monitors (21:9) have a much wider but shorter shape — same diagonal, completely different feel.

Phone screens vary too. Most modern phones use 20:9, but older models used 18:9 or 19.5:9. A 6.1-inch phone at 20:9 is taller and narrower than a 6.1-inch phone at 18:9.

Compare Without Measuring: Use a Visual Tool

If you don't have a tape measure — or you're comparing screens you don't own yet — use Easy Compare. It overlays any two screen sizes at true scale so you can see exactly how they differ:

• Phones: Compare the iPhone 16 vs 16 Plus or iPhone 16 Pro vs Pro Max
• Tablets: See iPad Air 11 vs iPad Pro 11 or iPad Pro 11 vs 13 inch
• TVs: Compare 55 vs 65 inch TV or 43 vs 65 inch TV

No math, no rulers — just select two devices and see the difference at real scale.

Quick Reference: Most Common Comparisons

Bottom Line

Screen size is measured diagonally, but area is what you actually see. A small bump in diagonal inches means a much bigger bump in usable space. Whether you measure with a tape at home or use a free online tool like Easy Compare, comparing screen areas — not just diagonals — is the key to picking the right size. For more on this topic, see our guides on screen area vs diagonal and what comparison charts don't tell you.