RatioSlateFrom the file
Image aspect ratio calculator
Open an image to read its real pixel size and ratio. Then compare crops from one focus point and export without sending the file anywhere.
Images are processed locally in your browser.
Direct answer
Start from the file, not from a typed size
Typed dimensions can be wrong. This page reads the width and height from the file you open, replaces the calculator fields with those pixels, and unlocks the ratio so you see the image’s own shape. After that, the same focus point drives every platform preview.
Quick reference
| Accepted | JPG, PNG, WebP |
|---|---|
| Limit | 50 MB, 80 megapixels, 32,768 px per side |
| Processing | Local browser only |
| After open | Fields switch to the image’s intrinsic size |
| Export | Current frame, or a ZIP of the selected presets |
Platform data sources
Working presets and safe-zone guidance are checked against official platform documentation. Safe zones remain conservative guides because app UI varies.
What changes when the file opens
The browser decodes the image, checks the type and pixel count, and stores it in a temporary object URL. Nothing is posted to a server. The width and height fields become the image’s natural size, and the ratio label follows those pixels. If you had locked a ratio while typing, that lock clears, because the file’s shape is now the source of truth.
Click the subject that must stay visible. Arrow keys nudge the point. Fill crop uses that point as the anchor. Fit scales the whole image inside the frame instead of cutting it. Safe-zone bands can be turned on for TikTok, Reels, or Shorts; they are drawn on the preview and are not burned into the exported pixels.
How this differs from the plain calculator
The aspect ratio calculator answers a pair of numbers you type. This page answers the pair inside a file, then shows what each preset does to that file. A 3:2 photo and a typed “3:2” are not the same job: only the file can show which part of the picture the crop keeps.
Examples
Square product photo into a feed and a reel
Open the file, confirm the detected ratio, then compare 4:5 and 9:16 before you export both.
A scan or screenshot
The detected size is whatever the file contains, including odd ratios. The label stays custom when it is not one of the five named shapes.
Frequently asked questions
Does opening an image change the typed dimensions?
Yes. The fields switch to the image’s intrinsic width and height, and any ratio lock is cleared.
Is the safe-zone overlay included in the download?
No. The overlay is only a preview. Exports are the cropped image at the selected pixel size.
Are my images uploaded to a server?
No. Image decoding, reframing, and export happen locally in your browser. The site does not receive your image file.
Which image formats can I use?
You can open JPG, PNG, and WebP images, then export JPG, PNG, or WebP files in supported browsers.