Aspect Ratio Calculator
Calculate and convert aspect ratios for video and photography. Scale dimensions while maintaining proportions for YouTube, Instagram, TikTok, and more.
Aspect Ratio Calculator
Calculate and convert aspect ratios for video and photography
Common Aspect Ratios
16:9
HD Video, YouTube
4:3
Standard TV, iPad
3:2
DSLR Photos
1:1
Instagram Square
21:9
Ultrawide Cinema
9:16
TikTok, Stories
Resolution Presets
Formula
Aspect Ratio = Width : Height (simplified)Find the simplified ratio and scale dimensions while maintaining proportions
How to Use
- 1Enter dimensions — Input your current width and height in pixels.
- 2View aspect ratio — See the simplified aspect ratio and decimal value.
- 3Scale dimensions — Enter a target width to calculate proportional height.
- 4Use presets — Click common ratios or resolution presets for quick setup.
Frequently Asked Questions
What is aspect ratio?
Aspect ratio is the proportional relationship between width and height of an image or video. Common ratios include 16:9 (widescreen), 4:3 (standard), and 1:1 (square).
What aspect ratio should I use for YouTube?
YouTube recommends 16:9 aspect ratio. Standard resolutions are 1920×1080 (1080p), 2560×1440 (1440p), and 3840×2160 (4K). YouTube will add black bars to videos with different ratios.
What aspect ratio is best for Instagram?
Instagram supports multiple ratios: 1:1 (square) for feed posts, 4:5 (portrait) for maximum feed visibility, 9:16 (vertical) for Stories and Reels, and 1.91:1 (landscape) for feed posts.
How do I maintain aspect ratio when resizing?
To maintain aspect ratio, multiply or divide both dimensions by the same factor. This calculator automatically calculates the correct height when you specify a target width.
What is the difference between 16:9 and 1.78:1?
They are the same ratio expressed differently. 16:9 is the simplified integer ratio, while 1.78:1 is the decimal equivalent (16÷9=1.78). Both represent standard HD widescreen.