How Do You Measure a Monitor Size?

Monitor size is measured diagonally from one corner of the visible screen to the opposite corner. Only the display area is measured — not the bezel or frame.

For example, if the diagonal measurement is around 23.8 inches, the monitor is marketed as a 24-inch display.

Step-by-Step Guide

Step 1: Get a Measuring Tape

Use a measuring tape or ruler. Make sure the monitor is turned off for easier measurement.

Step 2: Measure Diagonally

Place the tape at the bottom-left corner of the visible screen and extend it to the top-right corner.

How to measure monitor size

Do not include the surrounding plastic frame (bezel).

Common Monitor Sizes

Screen Size vs Screen Resolution

Screen size refers to physical measurement in inches. Resolution refers to pixel count (for example, 1920 × 1080).

Screen Size Resolution
24 inches 1920 × 1080
27 inches 2560 × 1440
32 inches 3840 × 2160 (4K)

How to Calculate Monitor Size Using Width & Height

If you know the width and height in inches, use this formula:

Diagonal = √(width² + height²)
    

Example:

Width = 20.9 inches
Height = 11.8 inches
Diagonal ≈ 24 inches
    

Frequently Asked Questions

Does monitor size include the bezel?

No. Only the visible display area is measured.

Can two monitors have the same resolution but different sizes?

Yes. Resolution does not determine physical screen size.

Can websites detect my monitor size automatically?

No. Browsers restrict access to physical measurements for privacy reasons.