Aspect Ratio Calculator
Calculate aspect ratios from any dimensions. Enter width and height to get the simplified ratio instantly. Includes visual preview and common presets.
Common Aspect Ratios
What is Aspect Ratio?
Aspect ratio is the proportional relationship between an image's width and height, expressed as two numbers separated by a colon (e.g., 16:9). It describes the shape of the image, not its size.
For example, both 1920×1080 and 3840×2160 share the same 16:9 aspect ratio — the second image is exactly twice as large, but maintains the same proportions.
How This Calculator Works
The calculator finds the Greatest Common Divisor (GCD) of your width and height, then divides both by that number to get the simplified ratio.
Example: 1920 × 1080
GCD = 120
1920 ÷ 120 = 16
1080 ÷ 120 = 9
Result: 16:9
When to Use Each Ratio
- 1:1 (Square): Instagram posts, profile pictures, album covers
- 4:3 (Classic): Traditional photography, presentations, old TVs
- 3:2 (Photography): 35mm film format, most DSLR cameras
- 16:9 (Widescreen): YouTube videos, HD monitors, modern TVs
- 21:9 (Ultrawide): Cinematic films, ultrawide monitors
- 9:16 (Vertical): Instagram Stories, TikTok, mobile-first video
- 4:5 (Portrait): Instagram feed posts (portrait orientation)