Screen Size Calculator

Calculate physical
screen dimensions instantly.

Enter resolution and diagonal to get inches, centimeters, PPI, and megapixels.

Screen Size Calculator

Calculate physical screen size, PPI, and aspect ratio from pixel dimensions.

Enter two values to calculate the third (positive numbers only).
PPIResult
Aspect RatioSimplified
Width (in)
Height (in)
Width (cm)
Height (cm)
Total PixelsPixels
MegapixelsMP
— MP

What is a Screen Size Calculator?

A screen size calculator determines physical screen dimensions from pixel resolution and diagonal measurement. It calculates PPI (Pixels Per Inch) using PPI = √(W² + H²) ÷ diagonal. Width and height in inches are derived by dividing pixels by PPI. Common examples: a 24" monitor at 1920×1080 ≈ 92 PPI, a 27" monitor at 2560×1440 ≈ 109 PPI. Remember: resolution (pixel count) differs from physical screen size (diagonal inches).

About Screen Size Calculator

This screen size calculator turns pixel resolution and diagonal measurement into physical screen dimensions in inches and centimeters. It is useful for anyone buying a monitor, planning a design layout, or checking whether a display meets a physical space requirement.

By entering width, height, and diagonal, you instantly get physical width and height, PPI, aspect ratio, and megapixel counts. It works for monitors, laptops, tablets, phones, and TVs.

What is Screen Size?

Screen size usually refers to the diagonal distance between two opposite corners of the display area. A 27-inch monitor means the diagonal measures 27 inches from corner to corner.

Physical width and height are smaller than the diagonal. A 24-inch 16:9 monitor is roughly 20.5 inches wide and 11.5 inches tall. Our display size calculator computes these exact measurements from resolution and diagonal.

How Screen Size is Calculated

First, the tool calculates PPI using the formula: PPI = √(width² + height²) ÷ diagonal inches. Then physical width = width ÷ PPI, and physical height = height ÷ PPI. The same values can be converted to centimeters by multiplying inches by 2.54.

This screen inches calculator performs the full chain automatically. No manual math, no separate PPI lookup, and no approximations.

Screen Size vs Resolution

Screen size is the physical measurement of the display. Resolution is the number of pixels arranged horizontally and vertically. A 24-inch 1080p monitor and a 27-inch 1080p monitor share the same resolution, but the larger screen has lower pixel density and softer images.

Our monitor size calculator helps you compare displays by showing both physical size and pixel density side by side.

Common Monitor Sizes

Popular monitor diagonals include 21.5", 24", 27", 32", and 34" for desktops, 13"–17" for laptops, and 6"–7" for phones. Within each size, monitor dimensions vary by aspect ratio.

  • 24" 16:9: about 20.9" × 11.7"
  • 27" 16:9: about 23.5" × 13.2"
  • 32" 16:9: about 27.9" × 15.7"
  • 34" 21:9 ultrawide: about 29.9" × 12.8"

Benefits

This free screen size calculator helps shoppers verify actual monitor dimensions before purchase. Designers use it to match mockups to real devices. Developers use it when planning responsive breakpoints and viewport sizes.

Because the tool reports inches, centimeters, PPI, and aspect ratio in one place, you rarely need to cross-reference multiple calculators. Results update live, so you can compare multiple configurations quickly.

Frequently Asked Questions