Free aspect ratio calculator. Enter width and height to get the simplified ratio. Scale dimensions proportionally or pick from 40+ platform presets.
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Aspect Ratio Calculator, Design, Free aspect ratio calculator. Enter width and height to get the simplified ratio. Scale dimensions proportionally or pick from 40+ platform presets., image aspect ratio, video resolution, width height ratio, 16:9 calculator, calc, compute
Aspect Ratio Calculator
Free aspect ratio calculator. Enter width and height to get the simplified ratio. Scale dimensions proportionally or pick from 40+ platform presets.
image aspect ratio, video resolution, width height ratio, 16:9 calculator
Design global
Aspect Ratio Calculator, Design, Free aspect ratio calculator. Enter width and height to get the simplified ratio. Scale dimensions proportionally or pick from 40+ platform presets., image aspect ratio, video resolution, width height ratio, 16:9 calculator, calc, compute
Aspect Ratio Calculator
Free aspect ratio calculator. Enter width and height to get the simplified ratio. Scale dimensions proportionally or pick from 40+ platform presets.
Enter width and height to calculate the simplified ratio.
px
px
Aspect Ratio
16:9
Widescreen HD
1920 × 1080 px
Dimensions
1920 × 1080
pixels
Orientation
landscape
layout
Decimal
1.7778
ratio
What 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
16:9
Widescreen HD
YouTube, most TVs, laptops, gaming monitors, video content. The global broadcast standard since 2009.
4:3
Standard TV / Film
Classic TV ratio, older monitors, iPad non-retina. Still used in some video formats and Zoom backgrounds.
1:1
Square
Instagram posts, profile pictures, thumbnails. Clean and platform-neutral for social media.
9:16
Vertical / Mobile
Instagram Stories, TikTok, YouTube Shorts, Reels. The vertical video standard for mobile-first content.
4:5
Instagram Portrait
Instagram feed portrait posts. Taller than square — maximizes screen real estate in the feed.
3:2
Classic Photo (DSLR)
Standard DSLR and mirrorless camera sensor ratio. Used in 35mm film photography.
21:9
Ultrawide
Ultrawide gaming monitors, cinematic movie format. Immersive widescreen experience.
Social Media Quick Reference
Recommended dimensions for major platforms
Instagram
Square Post
1:11080 × 1080 px
Instagram
Story / Reel
9:161080 × 1920 px
Instagram
Portrait Post
4:51080 × 1350 px
YouTube
Thumbnail
16:91280 × 720 px
LinkedIn
Post Image
1.91:11200 × 627 px
LinkedIn
Cover Photo
4:11584 × 396 px
Twitter/X
Post Image
16:91600 × 900 px
Twitter/X
Header
3:11500 × 500 px
TikTok
Video
9:161080 × 1920 px
Facebook
Cover Photo
~2.7:1851 × 315 px
Tips for Working with Aspect Ratios
Best practices to avoid distortion and get consistent results
1
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.
2
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.
3
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.
4
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
Divide both the width and height by their Greatest Common Divisor (GCD). For example, for 1920×1080: GCD(1920, 1080) = 120. So 1920÷120 = 16 and 1080÷120 = 9, giving you the ratio 16:9. This calculator does that automatically.
16:9 is the most widely used aspect ratio globally. It's the standard for HD and 4K televisions, YouTube videos, most laptop and desktop monitors, and digital video production. For mobile-first content, 9:16 (the vertical flip of 16:9) is increasingly dominant on platforms like TikTok, Instagram Stories, and YouTube Shorts.
Use the proportional scaling formula: New Height = (New Width × Original Height) ÷ Original Width. For example, to scale a 1920×1080 image to 1280 wide: New Height = (1280 × 1080) ÷ 1920 = 720px. Switch to Resize mode in this calculator to do this instantly.
Instagram supports several aspect ratios depending on the post type: Square posts use 1:1 (1080×1080 px), Portrait posts use 4:5 (1080×1350 px), Landscape posts use 1.91:1 (1080×608 px), and Stories/Reels use 9:16 (1080×1920 px). For the best feed coverage, 4:5 portrait is recommended as it takes up the most vertical space.
1920×1080 pixels has an aspect ratio of 16:9. This is the standard Full HD (1080p) resolution used by most TVs, monitors, YouTube videos, and streaming services. The GCD of 1920 and 1080 is 120, so 1920÷120 = 16 and 1080÷120 = 9.
A tire's aspect ratio is different from visual media — it refers to the sidewall height as a percentage of the tire's section width. For a tire labeled 205/55R16: the section width is 205mm and the aspect ratio is 55, meaning the sidewall height is 55% of 205mm = 112.75mm. This is a structural specification, not a visual ratio.
1.91:1 is a decimal notation for an aspect ratio that is approximately 1.91 times wider than it is tall. It's the standard for Open Graph (OG) images used in social media link previews (1200×630 px), Facebook posts, and LinkedIn post images. In simplified pixel terms, it's close to 1200:628 or 16.9:8.86.
Aircraft wing aspect ratio is calculated differently from screen or image ratios. It equals the wingspan squared divided by the wing area: AR = b² ÷ S, where b is wingspan and S is total wing area. A high aspect ratio (like a glider at 20:1+) means a long, narrow wing for efficient cruise. A low aspect ratio (like a fighter jet) means a short, wide wing for maneuverability.
4:3 is the older 'standard' TV and film ratio (nearly square), used by classic televisions, older monitors, and some tablet formats. 16:9 is the modern 'widescreen' ratio, almost twice as wide relative to height. If you display 4:3 content on a 16:9 screen, you get black bars (pillarboxing) on the sides. Displaying 16:9 content on 4:3 adds bars top and bottom (letterboxing).
Yes. Enter your video frame dimensions in the Width and Height fields to instantly get the simplified aspect ratio. Use Resize mode to calculate safe output dimensions for different platforms (e.g., downscaling 4K to 1080p or 720p while keeping 16:9). The Presets section also lists standard platform sizes for YouTube, Instagram, TikTok, and more.
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