Free Online Aspect Ratio Calculator

Calculate proportional dimensions for videos, photos, and displays with common presets like 16:9, 4:3, 1:1, and 9:16.

Standard Presets

Calculate Target Dimensions

16:9
Simplified Aspect Ratio 16 : 9
Client-Side Guarantee: Calculations occur entirely in your browser.

How to Use the Aspect Ratio Calculator

  1. Select a common ratio preset or enter custom original dimensions.
  2. Enter a new width or height to calculate the proportional corresponding dimension.
  3. Review the visual preview box to confirm framing.

Key Features

✓ Calculate missing width or height based on custom or standard ratios
✓ Standard presets for 16:9 (YouTube/HDTV), 9:16 (Reels/TikTok), 4:3, 1:1, 21:9, and 3:2
✓ Simplifies arbitrary pixel dimensions into lowest common term ratios (e.g. 1920x1080 -> 16:9)
✓ Visual preview box demonstrating the rendered ratio

About Aspect Ratio Calculator

Quickly calculate missing dimensions while preserving exact aspect ratios. Perfect for video production, social media posts, photography, and responsive web design.

Frequently Asked Questions

What is the standard aspect ratio for YouTube videos and thumbnails?

The standard widescreen aspect ratio is 16:9 (e.g., 1920x1080 for Full HD and 1280x720 for thumbnails).

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