ToolSpotAI

Screen Resolution & Aspect Ratio Calculator

Calculate screen resolution, aspect ratio, PPI, and resize dimensions. Presets for phones, monitors, social media, and print.

Developer

Resolution

1920 × 1080

Aspect Ratio

16:9

Total Pixels

2,073,600

Megapixels

2.1 MP

Orientation

Landscape

PPI

82

1920 × 1080
16:9

Common Resolutions

NameResolutionRatioType
HD (720p)1280 × 72016:9TV
Full HD (1080p)1920 × 108016:9TV
QHD / 2K2560 × 144016:9Monitor
4K / UHD3840 × 216016:9TV
5K5120 × 288016:9Monitor
8K / UHD7680 × 432016:9TV
iPhone 15 Pro1179 × 2556131:284Mobile
iPhone 15 Pro Max1290 × 2796215:466Mobile
Samsung S24 Ultra1440 × 31206:13Mobile
iPad Pro 12.9"2048 × 2732512:683Tablet
MacBook Pro 14"3024 × 1964756:491Laptop
MacBook Pro 16"3456 × 22341728:1117Laptop
Instagram Post1080 × 10801:1Social
Instagram Story1080 × 19209:16Social
YouTube Thumbnail1280 × 72016:9Social
Twitter Header1500 × 5003:1Social
Facebook Cover820 × 312205:78Social
A4 @ 300dpi2480 × 3508620:877Print
Letter @ 300dpi2550 × 330017:22Print
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What is Screen Resolution & Aspect Ratio Calculator?

A screen resolution calculator helps you understand display specifications, calculate aspect ratios, determine PPI (pixels per inch), and resize images proportionally. Essential for designers, developers, photographers, and content creators who work with multiple screen sizes and formats. Our tool has three modes: Resolution Info (analyze any resolution), Aspect Ratio calculator (find dimensions for any ratio), and Resize Calculator (scale images proportionally). It includes presets for phones, monitors, social media, and print formats.

How It Works

Resolution Info: Enter width, height, and optional diagonal size to see aspect ratio, total pixels, megapixels, PPI, and a visual preview. Aspect Ratio: Enter a ratio (e.g., 16:9) and one known dimension to calculate the other. Resize: Enter original dimensions and a target width or height to get proportionally scaled dimensions.

Formula

Aspect Ratio = Width/GCD : Height/GCD
PPI = √(W² + H²) / Diagonal inches
Megapixels = W × H / 1,000,000
Resize: New Height = Target Width × (Original H / Original W)

Formula Explained

The GCD (Greatest Common Divisor) reduces the width:height ratio to simplest form. PPI uses the Pythagorean theorem to find the diagonal resolution in pixels, then divides by the physical diagonal size. Proportional resizing maintains the ratio by scaling both dimensions by the same factor.

Example

27" 4K Monitor (3840 × 2160): Aspect Ratio: 16:9 Total Pixels: 8,294,400 Megapixels: 8.3 MP PPI: √(3840² + 2160²) / 27 = 163 PPI Orientation: Landscape

Tips & Best Practices

  • ✓For web design, test layouts at 1920×1080 (most common desktop) and 375×812 (iPhone).
  • ✓Use 2x resolution assets for Retina/HiDPI displays (e.g., 2× the CSS pixel dimensions).
  • ✓300 PPI is the standard for print quality — check before sending to a printer.
  • ✓Social media platforms may compress images — upload at their exact recommended dimensions.
  • ✓Ultrawide monitors (21:9) are great for productivity but some content won't fill the screen.

Common Use Cases

  • •Finding aspect ratio and PPI of any display
  • •Calculating correct social media image dimensions
  • •Proportionally resizing images for different platforms
  • •Determining print quality from image resolution
  • •Comparing screen specifications when buying monitors or phones

Frequently Asked Questions

Aspect ratio is the proportional relationship between width and height, simplified to the smallest whole numbers. 1920×1080 has ratio 16:9 (divide both by GCD 120). 2560×1440 is also 16:9. Common ratios: 16:9 (widescreen), 4:3 (classic), 21:9 (ultrawide), 1:1 (square).

PPI measures pixel density — how many pixels fit per inch of screen diagonal. Higher PPI = sharper display. Formula: PPI = √(width² + height²) / diagonal inches. A 27" 4K monitor has ~163 PPI. iPhone 15 Pro has ~460 PPI. 300 PPI is the standard for print quality.

Instagram post: 1080×1080 (1:1). Instagram story: 1080×1920 (9:16). YouTube thumbnail: 1280×720 (16:9). Facebook cover: 820×312. Twitter header: 1500×500. LinkedIn banner: 1584×396. TikTok: 1080×1920 (9:16).

To maintain aspect ratio, only change one dimension and calculate the other. If original is 1920×1080 (16:9) and you want width 1280: new height = 1280 × (1080/1920) = 720. Use our Resize Calculator mode — enter one dimension and the other is computed automatically.

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