Aspect Ratio Calculator

Use the form below to calculate the missing value for a particular aspect ratio.

What is an Aspect Ratio Calculator?

An Aspect Ratio Calculator helps you find or convert the proportional relationship between the width and height of an image, video, or screen. The aspect ratio defines how wide or tall a frame is in comparison to its height — for example, a 16:9 ratio means that for every 16 units of width, there are 9 units of height.

This calculator instantly computes missing width or height values, so you can resize images, videos, or design layouts while preserving the same proportions. It's especially useful for photographers, designers, and video editors who need consistent scaling across multiple media formats.

What is an Aspect Ratio?

The aspect ratio is the proportional relationship between width and height, expressed as two numbers separated by a colon (e.g., 16:9 or 4:3). It tells you how an image or video’s shape compares horizontally versus vertically. For example:

• 16:9 — Widescreen format used in most modern TVs, monitors, and YouTube videos.
• 4:3 — Traditional format used in older television and computer screens.
• 1:1 — Perfect square, popular on Instagram posts.
• 21:9 — Ultra-wide ratio, common in cinema screens and ultrawide monitors.

How to Use This Tool

1. Enter your known width and height values, or select a common aspect ratio from the dropdown.
2. If you only know one dimension (width or height), enter it under “Width 2” or “Height 2” — the calculator will compute the other automatically.
3. Check the “Round results” box if you want whole number results.
4. View your ratio and a live preview box showing how the aspect ratio looks visually.

Example

Example 1: You have an image that is 1920 × 1080 pixels.

The calculator shows this as a 16:9 aspect ratio — standard Full HD widescreen format.

Example 2: You only know a width of 1280 pixels and want to maintain a 16:9 aspect ratio.

The calculator will automatically compute the height as 720 pixels.

Why Use an Aspect Ratio Calculator?

• Maintain proportions: Prevent images or videos from stretching or appearing distorted.
• Design consistency: Create responsive layouts that look perfect on any device or screen size.
• Video editing: Adjust resolution while keeping the cinematic or standard aspect intact.
• Photography: Crop images precisely without changing their visual balance.

Common Aspect Ratios Explained

16:9 → Widescreen (HD, Full HD, 4K, YouTube, TVs)
4:3  → Standard (Old monitors, projectors)
1:1  → Square (Instagram, profile pictures)
3:2  → DSLR photography aspect
21:9 → Cinematic ultrawide displays
  

Who Can Benefit From This Tool?

• Web and graphic designers creating responsive layouts
• Video editors preparing content for social media or TV
• Photographers adjusting image crops and resizing
• UI/UX designers maintaining visual balance across devices
• Developers defining consistent aspect ratios in CSS or apps

Why This Tool Stands Out

• Instant calculations — no downloads or logins
• Private and secure — runs entirely in your browser
• Auto-preview — visualize the ratio instantly
• Supports custom ratios and rounding for precision