Free Developer Tool

Visual Aspect Ratio Calculator

Calculate proportional dimensions for images, videos, and UI design. Instantly convert 16:9, 4:3, and custom screen resolutions with live visual previews.

Ratio
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Scale
No target
Output
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Resize while keeping the same proportion

Set the original size, then type a new width or height.

Original Size
This is your base ratio.
Set base size
Source width
Source height
Target Size
Fill one value and the other updates.
Edit width or height
Height auto-calculates
Width auto-calculates
Aspect Ratio
? : ?
Scale Change
No target
Target Size
Waiting

How to Calculate Aspect Ratio

The aspect ratio of an image describes the proportional relationship between its width and its height. Our calculator uses the standard mathematical formula: (Original Height / Original Width) × New Width = New Height.

Common Aspect Ratios in 2024

Quick Reference: Common Aspect Ratios

Requirement Preferred Ratio Resolution Example
YouTube Standard 16:9 1920 x 1080 (Full HD)
Instagram Square 1:1 1080 x 1080
TikTok / Reels / Shorts 9:16 1080 x 1920 (Vertical)
Classic TV / iPad 4:3 1024 x 768
Ultrawide Monitor 21:9 3440 x 1440

Frequently Asked Questions

The standard aspect ratio for modern screens and YouTube is 16:9. HD resolutions like 1080p and 4K follow this widescreen format.

Divide the width by the height. For example, an 800x600 image has a ratio of 1.33, which simplifies to 4:3.

Instagram and TikTok primarily use 9:16 (Vertical) for Stories and Reels. For standard feed posts, 1:1 (Square) or 4:5 (Vertical) is recommended to maximize screen real estate.

16:9 is widescreen for modern displays, while 4:3 is the older, boxier format used in legacy television.

If you change the ratio without cropping, the image will look stretched. Always calculate proportional dimensions to maintain visual integrity.

Yes, 21:9 is the cinematic 'Ultrawide' ratio. It is commonly used in film production and for gaming monitors to provide a wider field of vision compared to the standard 16:9.

21:9 is an Ultrawide ratio used in cinema and high-end gaming monitors for a wider field of view.