Choose the output shape first
Before generating an AI image, decide whether it will become a website hero, a square post, a vertical story, a thumbnail, or a banner. The final placement should guide the aspect ratio so you do not need heavy cropping later.
Common AI image ratios
Use 16:9 for website heroes and YouTube-style thumbnails, 1:1 for profile and icon-like images, 4:5 for portrait feed posts, 9:16 for vertical stories, and 21:9 for wide cinematic website sections.
Prompt with safe composition
Ask for extra space around the subject if you plan to add text, buttons, product labels, or UI overlays. Centered subjects are easier to crop into multiple sizes than subjects placed at the edge of the frame.
Resize without distortion
Do not stretch an AI image to fit a new ratio. Crop, extend, or regenerate the asset at the right shape. Use the aspect ratio calculator to find matching dimensions before exporting the final file.
AI prompt ratio examples
Pick the final crop before generating. These examples help keep AI outputs reusable across websites and social posts.
| Use case | Ratio | Example size | Prompt note |
|---|---|---|---|
| Website hero | 16:9 | 1920 × 1080 | Leave side space for headline text. |
| Social portrait | 4:5 | 1080 × 1350 | Keep subject centered and not too close to edges. |
| Vertical story | 9:16 | 1080 × 1920 | Allow room for captions and platform UI. |
| Icon / profile | 1:1 | 1024 × 1024 | Use simple composition that survives circular crop. |