Aspect Ratio Calculator
Calculate pixel width or height for any aspect ratio including 4:3, 16:9, 21:9, and custom ratios.
Enter one dimension to get the other.
Enter an aspect ratio and one dimension — the other calculates instantly.
An aspect ratio describes the proportional relationship between width and height.
Common aspect ratios:
- 4:3: Classic TV and monitors (e.g. 1024×768, 1600×1200)
- 16:9: Widescreen standard (e.g. 1920×1080, 3840×2160)
- 16:10: Common laptop screens (e.g. 1920×1200, 2560×1600)
- 21:9: Ultrawide monitors (e.g. 2560×1080, 3440×1440)
- 1:1: Square (e.g. Instagram posts)
How it works: Given a ratio W:H and one dimension, the other is calculated:
- Height = Width × (H / W)
- Width = Height × (W / H)
Example: For 16:9 with width 1920: Height = 1920 × (9/16) = 1080 pixels