Aspect Ratio Calculator

Free, private, runs in your browser.

What is Aspect Ratio Calculator?

Aspect Ratio Calculator is a free online tool that changes the width, height or resolution of an image. It runs in your browser with JavaScript and the canvas API, so your photos are never uploaded to a server and there is no sign-up, watermark or daily limit. It belongs to our Resize collection of 95 image tools.

This tool needs no settings: apply it and download.

How to use Aspect Ratio Calculator

  1. Open Aspect Ratio Calculator and drop, paste (Ctrl+V) or select your image.
  2. Adjust the options and watch the live preview.
  3. Hold the original button or use the before/after slider to compare.
  4. Press Apply to keep the change. Undo and redo are always available.
  5. Choose PNG, JPG, WEBP, AVIF or ICO, then download, copy or share the result.

Benefits

  • Private: files stay on your device
  • Fast: results appear instantly as you change settings
  • Free: no account, watermark or limits
  • Flexible: batch ZIP download for many files at once
  • Works on mobile, tablet and desktop

Features

Live preview, zoom and pan, before and after comparison, fullscreen view, undo and redo, copy to clipboard, share, keyboard shortcuts (Ctrl+Z, Ctrl+Y, Ctrl+S, Ctrl+V) and a download history.

When to use Aspect Ratio Calculator

Typical uses include profile pictures, print sizes, website thumbnails and upload limits. Keep the aspect ratio locked so the picture is not stretched. Upscaling cannot add real detail.

Aspect Ratio Calculator FAQ

Is Aspect Ratio Calculator free?

Yes. Aspect Ratio Calculator on Imagine Tool is free, with no sign-up, no watermark and no daily limit.

Are my images uploaded to a server?

No. Aspect Ratio Calculator runs entirely in your browser, so your images never leave your device.

Which image formats does Aspect Ratio Calculator support?

Any image your browser can open, including JPG, PNG, WEBP and GIF, and often AVIF. You can export PNG, JPG, WEBP, AVIF or ICO.

Will resizing reduce quality?

Making an image smaller keeps it sharp. Enlarging uses smoothing, so very large increases look softer.

Does Aspect Ratio Calculator work on mobile?

Yes. The page is fully responsive and works on phones, tablets and desktops.

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