Mode
Width × Height
px (or any unit)
About This Calculator
An aspect ratio describes the proportional relationship between width and height. It's expressed as W:H (e.g. 16:9) or as a decimal (1.778).
Common aspect ratios
- 16:9 — Widescreen HD/4K TV, YouTube, most monitors
- 4:3 — Older TVs, tablets, many cameras
- 1:1 — Square (Instagram, profile photos)
- 21:9 — Ultra-wide monitors, cinema
- 3:2 — DSLR cameras, 35mm film
Frequently asked questions
How does this aspect ratio calculator work?
The aspect ratio calculator simplifies a width and height to their lowest ratio (for example 1920×1080 becomes 16:9) and can also scale dimensions to a new size while keeping the same proportions.
How do I calculate an aspect ratio?
Divide the width and height by their greatest common divisor. For example, 1920 and 1080 share a divisor of 120, which gives 16:9. The tool does this for any dimensions.
How do I resize an image without distortion?
Use the scale mode: enter your original size and one new dimension, and the tool calculates the other dimension to preserve the exact aspect ratio.