Aspect Ratio Calculator
Calculate matching width or height while preserving image and video aspect ratio, with 16:9, 9:16, 4:3, square, and ultrawide examples.
Loading tool...
Calculate matching dimensions while preserving aspect ratio
Aspect Ratio Calculator finds the matching width or height while keeping the original image or video ratio. It is useful for thumbnails, short-form videos, presentations, blog images, and common formats such as 16:9, 9:16, 4:3, and 1:1.
Useful For
- Calculate 16:9 video thumbnail dimensions
- Resize 9:16 short-form images
- Keep original ratio while changing width or height
Good To Know
Each platform may have different recommended resolution and safe-area rules. Check the latest upload guidelines before publishing.
File Handling Notes
File tasks are browser-first when practical. Large files, encrypted documents, and formats that need server conversion can be limited by browser memory and server support.
Private File Handling
Jabdogu processes supported file tasks in the browser first and uploads only when server conversion is required. This note was reviewed on Jul 1, 2026.
Aspect ratio checks
Original
- Enter original width and height pixels accurately
- For rotated photos, use the displayed orientation
Target size
- Fix either width or height and calculate the other
- Check platform ratios such as 16:9, 9:16, or 1:1
Before applying
- Check text and faces after resizing
- Separate keeping ratio from cropping when the destination requires a crop
Yes. Enter a target width or height and the matching dimension is calculated so images and videos keep their original ratio.
Yes. Common formats such as 16:9, 9:16, 4:3, and 1:1 are useful for thumbnails, shorts, reels, and presentations.
Image editors usually need whole pixels, so results are often rounded. For critical work, confirm the final size in your editing tool.