Utility
Aspect Ratio Calculator
Calculate aspect ratios from width and height, or use presets for common social media platforms. Find compatible formats instantly.
Enter dimensions or select a preset
Aspect Ratio
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Social Media Compatibility
How is this calculated?
Formula: GCD-based ratio reduction and dimension calculation.
Aspect Ratio:
GCD = Greatest Common Divisor of (width, height)
ratio = (width ÷ GCD) : (height ÷ GCD)
Decimal Ratio:
decimal = width ÷ height
Megapixels:
MP = (width × height) ÷ 1,000,000
Missing Dimension (from preset):
height = width × (ratio_h ÷ ratio_w)
width = height × (ratio_w ÷ ratio_h)
Example: 1920×1080
GCD(1920, 1080) = 120
Ratio = 1920/120 : 1080/120 = 16:9
Decimal = 1920/1080 = 1.778Calculation history
No calculations yet.
FAQ
Frequently asked questions
What is aspect ratio and why does it matter?
Aspect ratio is the proportional relationship between width and height of an image or screen. It's expressed as width:height (e.g., 16:9). It matters because using the wrong aspect ratio causes stretching, cropping, or letterboxing. Each social media platform and display type has preferred aspect ratios for optimal viewing.
What aspect ratio should I use for YouTube videos?
YouTube's standard is 16:9 (1920×1080 for Full HD, 3840×2160 for 4K). YouTube Shorts use 9:16 (1080×1920) for vertical video. While YouTube accepts other ratios, 16:9 fills the player completely on desktop and TV screens without black bars. For YouTube thumbnails, use 16:9 at 1280×720 pixels minimum.
What are the best aspect ratios for social media?
Instagram Feed: 1:1 (square) or 4:5 (portrait). Instagram Stories/Reels: 9:16. TikTok: 9:16. Facebook Feed: 1.91:1 or 1:1. X/Twitter: 16:9. LinkedIn: 1.91:1 or 1:1. Pinterest: 2:3. Each platform may crop images that don't match their preferred ratio, so design with the target ratio in mind.
How do I calculate the missing dimension from an aspect ratio?
If you know one dimension and the ratio, calculate the other: For 16:9 with width 1920: height = 1920 × (9÷16) = 1080. For 16:9 with height 720: width = 720 × (16÷9) = 1280. The formula is: missing = known × (ratio_missing ÷ ratio_known).
What is the difference between 16:9 and 16:10 aspect ratios?
16:9 (1.78:1) is the standard for TVs, YouTube, and most video content. 16:10 (1.6:1) is slightly taller and was common in older computer monitors and some current laptops (like MacBook). The difference is subtle — 16:10 gives about 11% more vertical space, which some prefer for productivity and web browsing.