Aspect Ratio Calculator
Resize images and video without distortion
Common Resolutions
| Name | Resolution | Ratio | Use |
|---|---|---|---|
| HD (720p) | 1280 × 720 | 16:9 | YouTube, streaming |
| Full HD (1080p) | 1920 × 1080 | 16:9 | Standard video |
| 2K (QHD) | 2560 × 1440 | 16:9 | Gaming monitors |
| 4K (UHD) | 3840 × 2160 | 16:9 | Premium video |
| Instagram Post | 1080 × 1080 | 1:1 | Feed posts |
| Instagram Story | 1080 × 1920 | 9:16 | Stories, Reels |
| Twitter Post | 1600 × 900 | 16:9 | Timeline images |
| Facebook Cover | 820 × 312 | ~2.6:1 | Profile banner |
Why Aspect Ratio Matters
Aspect ratio is the proportional relationship between width and height. A 16:9 ratio means for every 16 units of width, there are 9 units of height. When you resize an image or video, maintaining the aspect ratio prevents distortion — stretching people into unnatural proportions or compressing circles into ovals. Every professional design tool locks aspect ratio by default during resizing for exactly this reason.
The most common aspect ratios in 2026: 16:9 dominates video (YouTube, Netflix, TV broadcasts), 1:1 dominates social media feeds (Instagram, Facebook), 9:16 dominates vertical video (TikTok, Instagram Stories, YouTube Shorts), and 4:3 persists in presentation slides (PowerPoint, Keynote) and older photography. Ultrawide monitors use 21:9, which provides more horizontal workspace for video editing and gaming.
How do I calculate aspect ratio from pixel dimensions?
Divide both width and height by their greatest common divisor (GCD). For 1920×1080: GCD(1920,1080) = 120. Divide both: 1920/120 = 16, 1080/120 = 9. Ratio: 16:9. This calculator does it automatically for any dimensions you enter.