When the ratio is locked, changing width or height updates the other side to keep the same shape.
Current ratio
--Enter dimensions to render the frame preview, ratio details, and scaled sizes.
Quick presets
LiveEnter width and height to see the ratio, frame shape, and a copy-ready CSS snippet.
Input size
When the ratio is locked, changing width or height updates the other side to keep the same shape.
Current ratio
--Enter dimensions to render the frame preview, ratio details, and scaled sizes.
Quick presets
LivePreview stage
Primary frame
Add dimensions to see whether the frame feels closer to a cover, poster, or widescreen canvas.
Preview updates live as you switch examples, fit modes, and dimensions.
Common width scaling
These cards show the matching height for a few practical widths.
Quick guide
Compact below-tool notes that help first-run users and repeated visitors move faster without changing the main interface.
Chinese search: 長寬比 計算機、圖片比例 計算、aspect ratio 計算
How to use
Examples
FAQ
No. It calculates ratio math and preview framing only.
Yes. It is designed to help you move from visual planning into CSS quickly.