Aspect Ratio Calculator
Calculate aspect ratios
Frequently Asked Questions
How do I calculate aspect ratio from width and height?
Divide both dimensions by their greatest common divisor (GCD). 1920×1080: GCD is 120, so 1920/120 : 1080/120 = 16:9. The tool calculates the ratio instantly and shows equivalent resolutions for common display sizes.
What are common aspect ratios for video and photos?
16:9: HD/4K video, widescreen monitors. 4:3: traditional TV, iPad. 1:1: Instagram square. 9:16: TikTok, Instagram Stories. 21:9: ultrawide monitors. 3:2: DSLR photos. 2.39:1: cinema widescreen. The tool converts between all ratios.
How do I resize an image while maintaining aspect ratio?
Set one dimension (width or height) and the tool calculates the other. For 16:9 at 1280 width: height = 1280 × 9/16 = 720. This prevents stretching or distortion. The tool shows the calculated dimension for any target size.
What aspect ratio should I use for social media?
Instagram feed: 1:1 (1080×1080) or 4:5 (1080×1350). Stories/Reels: 9:16 (1080×1920). Facebook: 1.91:1 (1200×628). Twitter: 16:9 (1200×675). YouTube thumbnail: 16:9 (1280×720). LinkedIn: 1.91:1 (1200×627).
How do I convert between aspect ratios without cropping?
You can't change aspect ratio without cropping or adding letterboxing/pillarboxing (black bars). 16:9 to 4:3: crop sides or add pillarbox. 4:3 to 16:9: crop top/bottom or add letterbox. The tool shows the crop area for any conversion.