Calculate proportional width, height, aspect ratio, and megapixels for common video and image formats without changing the selected ratio.
Aspect ratio describes the proportional relationship between a frame's width and height. This calculator keeps the selected ratio locked while you change either dimension, then calculates the matching dimension automatically. It also simplifies the ratio and shows the total pixel count in megapixels.
The tool is designed for planning and resizing workflows. It calculates dimensions in pixels; it does not crop, encode, render, or export a video file.
| Format | Aspect Ratio | Example Dimensions | Typical Workflow |
|---|---|---|---|
| Vertical video | 9:16 | 1080 × 1920 px | Reels, Shorts, TikTok |
| Widescreen video | 16:9 | 1920 × 1080 px | YouTube and standard HD video |
| Portrait image/video | 4:5 | 1080 × 1350 px | Portrait social posts |
| Square | 1:1 | 1080 × 1080 px | Square posts and graphics |
These are common working dimensions, not a guarantee of a platform's current upload requirements. Check the destination platform or service when a project has a specific technical specification.
Width = Height × ratio width ÷ ratio height.
Height = Width × ratio height ÷ ratio width.
The calculator uses the greatest common divisor to reduce a width and height to the simplest ratio.
9:16 is a proportion, not a single resolution. 1080 × 1920 pixels is a common example of a 9:16 vertical frame. Other dimensions such as 720 × 1280 and 2160 × 3840 keep the same ratio.
16:9 can use many resolutions. Common examples include 1920 × 1080 for Full HD and 3840 × 2160 for 4K.
Keep the target aspect ratio fixed and calculate the matching width or height before changing your editing timeline or canvas size. This calculator performs that proportional calculation automatically.
No. It only calculates dimensions and previews the selected proportion. Use your video editor or image editor to perform the actual crop, resize, or export.
The calculator keeps the current aspect ratio locked. Changing one dimension therefore recalculates the other dimension to preserve the same proportions.
Yes. The calculator runs directly in the browser and is available without an account or paid plan.