ganak.appAspect Ratio Calculator
Free aspect ratio calculator. Enter width & height to get the simplified ratio (16:9, 4:3, 1:1). Scale dimensions proportionally, or pick from 40+ presets for Instagram, YouTube, LinkedIn, TikTok, and more.
Enter width and height to calculate the simplified ratio.
Aspect Ratio
16:9
Widescreen HDWhat Is an Aspect Ratio?
The proportional relationship between width and height of any visual media
An aspect ratio describes the proportional relationship between the width and height of an image, video, screen, or any rectangular object. It is expressed as two numbers separated by a colon — such as 16:9 or 4:3 — representing the ratio of width to height.
16:9
universal video
Global broadcast standard
9:16
mobile & stories
TikTok, Reels, Shorts
3:2
DSLR sensor
Classic photography
Example: A 1920×1080 pixel image has an aspect ratio of 16:9. This means for every 16 units of width, there are 9 units of height — whether scaled up to 3840×2160 (4K) or down to 1280×720 (HD).
How Is Aspect Ratio Calculated?
The GCD method for finding the simplest form
The simplest way to express an aspect ratio is to divide both width and height by their Greatest Common Divisor (GCD) — the largest number that divides both values evenly.
GCD Formula — 1920 × 1080
GCD
120
of 1920, 1080
Width
16
1920 ÷ 120
Height
9
1080 ÷ 120
Result: 16:9
Proportional Scaling
New Height = (New Width × Original Height) ÷ Original Width
New Width = (New Height × Original Width) ÷ Original Height
Example: Scaling 1920×1080 to width 1280 → New Height = (1280 × 1080) ÷ 1920 = 720 px
Common Aspect Ratios and Their Uses
The ratios you'll encounter most in design, video, and photography
Widescreen HD
YouTube, most TVs, laptops, gaming monitors, video content. The global broadcast standard since 2009.
Standard TV / Film
Classic TV ratio, older monitors, iPad non-retina. Still used in some video formats and Zoom backgrounds.
Square
Instagram posts, profile pictures, thumbnails. Clean and platform-neutral for social media.
Vertical / Mobile
Instagram Stories, TikTok, YouTube Shorts, Reels. The vertical video standard for mobile-first content.
Instagram Portrait
Instagram feed portrait posts. Taller than square — maximizes screen real estate in the feed.
Classic Photo (DSLR)
Standard DSLR and mirrorless camera sensor ratio. Used in 35mm film photography.
Ultrawide
Ultrawide gaming monitors, cinematic movie format. Immersive widescreen experience.
Social Media Quick Reference
Recommended dimensions for major platforms
Square Post
Story / Reel
Portrait Post
YouTube
Thumbnail
Post Image
Cover Photo
Twitter/X
Post Image
Twitter/X
Header
TikTok
Video
Cover Photo
Tips for Working with Aspect Ratios
Best practices to avoid distortion and get consistent results
Always scale from the ratio, not the pixel count
When resizing images, use the original ratio to derive new dimensions. Changing width and height independently distorts your content.
Pixel aspect ratio vs display aspect ratio
Most digital images use square pixels (PAR 1:1). Legacy video formats like DVD use non-square pixels — always check before converting.
Safe zones for social media
Even with the correct ratio, keep important content in the center 80% — platforms often crop or overlay UI elements at the edges.
Use 16:9 as your universal default
If you're unsure what ratio to use for video content, 16:9 is the safest choice — it's the standard for YouTube, TV, and most digital displays.
Frequently Asked Questions
Common questions about aspect ratios, image scaling, and social media dimensions