Image Aspect Ratio Calculator
Drop in an image to instantly inspect its pixel dimensions, ratio, orientation and megapixels. Processing stays in your browser.
Inspect an image
JPG, PNG, WebP, GIF and morePreview
Local preview onlyWhy check an image's aspect ratio?
Aspect ratio matters whenever an image has to fit a fixed frame, thumbnail, social post, website component or video canvas. Knowing the original ratio helps you decide whether to resize or crop.
How to check an image's aspect ratio
- Select or drag an image into the checker.
- Your browser reads the image's intrinsic pixel width and height.
- The tool simplifies those dimensions into a ratio and reports the decimal value, orientation and megapixels.
- Compare the result with the required frame, then resize proportionally or calculate a crop if the shapes differ.
The reported megapixel value is width multiplied by height, divided by one million. It is useful for comparing pixel counts, but it does not by itself measure focus, compression quality or print sharpness.
Private, browser-based inspection
The selected image is decoded locally using browser APIs. AspectRatioZ creates a temporary local preview URL, reads the natural dimensions and releases that URL when you replace or clear the image, or leave the page. The file is not sent to an AspectRatioZ server.
Supported formats depend on the browser and device. If a file does not open, convert it to a widely supported web format such as JPEG, PNG or WebP and try again.
megapixels = width × height ÷ 1,000,000Example: 4000 × 3000 = 12 MP and simplifies to 4:3.
What the results tell you
- Dimensions: the intrinsic width and height in pixels.
- Simplified ratio: the smallest equivalent whole-number width-to-height relationship.
- Decimal ratio: width divided by height, useful for comparing uncommon shapes.
- Orientation: landscape, portrait or square.
- Megapixels: total pixel count expressed in millions.
Two images may have the same ratio but very different resolutions. Check both before delivery.
Use an image check to choose your next edit
Example brief: a website card needs a 1200 × 630 image, and the source photo is 4000 × 3000. The target is a sample design requirement, not a universal social-media specification.
- Choose the original photo above. For these dimensions, the checker reports 4:3, landscape and 12 MP. Read the actual values for your own image rather than assuming the example applies.
- Compare shapes: 1200:630 simplifies to 40:21, so a proportional resize alone cannot fill the card. Use the crop workflow to plan what to remove, or the fixed-frame fit calculator if the complete image must remain visible.
- Make the chosen edit in your image editor and export a separate file. The checker does not crop, compress or change the source.
- Load the exported copy here. Confirm 1200 × 630 and 40:21, then inspect the actual page preview for clipped faces or text.
Different task? If the destination has the same ratio, use the proportional resize walkthrough. For paper output, check print size and effective PPI. For responsive HTML, use the srcset generator after exporting the required image variants.
Pixel dimensions confirm size, not sharpness, accessibility or compressed file weight. Check those separately in the final context; a high megapixel count does not guarantee a good image.
Frequently asked questions
Is my image uploaded?
No. The browser reads it locally to display dimensions and a preview.
Does the checker store my image?
No server upload or account storage is used. Reloading or leaving the page clears the current preview.
Why is my ratio a large pair of numbers?
The exact pixel dimensions may simplify only slightly. The decimal value can help you compare the result with a nearby common ratio without incorrectly labeling it as exact.
Are file size and resolution the same?
No. Resolution is width × height in pixels. File size is affected by format, compression, image detail and metadata.
Can the checker crop or resize the image?
No. It inspects the source. Use the reported dimensions with the converter and an editing application.