Keep recording and editing together. ScreenBuddy adds zoom, captions, and local MP4 or GIF export on Mac and Windows.
Download freeHow it works
Pick or type a resolution
Use a preset like 1080p or enter custom width and height.
Add the diagonal size
Enter the screen’s diagonal in inches to compute pixel density.
Read the metrics
Get PPI, total megapixels, the simplified aspect ratio, and dot pitch.
Understand any display’s sharpness
Resolution alone does not tell you how sharp a screen looks — a 4K phone and a 4K TV have wildly different clarity because pixel density depends on both the pixel count and the physical size. This calculator combines them into the numbers that actually matter: PPI, total pixels, aspect ratio, and dot pitch.
How do I calculate PPI from width, height, and diagonal?
PPI = √(width² + height²) ÷ diagonal-in-inches. A 1920×1080 panel has a ~2203-pixel diagonal; on 24 inches that is about 92 PPI. On a 27-inch 1440p display you land near 109 PPI; the same 27-inch size in 4K is about 163 PPI. Higher PPI helps UI text in a recording, but capture size and export size still have to match the player.
Why it’s useful
- Buying a monitor — compare sharpness across sizes and resolutions.
- Designing UI — know the real density your work will render at.
- Recording screens — match your capture resolution to the display so labels stay readable after you scale the video down.
Pair this with the aspect ratio calculator for export pixels and the bitrate calculator for file size. Planning a product walkthrough? ScreenBuddy for Mac and Windows lets you edit locally, choose a common output shape, and export MP4 or GIF after licensing.
Frequently Asked Questions
Put the Screen Resolution Calculator on your own site
Free to embed, with no account required. Paste the code where you want the tool. The frame uses lazy loading, and the credit line is optional.
<iframe src="https://screenbuddy.xyz/embed/screen-resolution-calculator" title="Screen Resolution Calculator" width="100%" height="640"
style="border:0;max-width:720px;border-radius:12px" loading="lazy"></iframe>
<p style="font:14px/1.5 system-ui,sans-serif;margin:8px 0 0">
<a href="https://screenbuddy.xyz/tools/screen-resolution-calculator" rel="nofollow">Screen Resolution Calculator</a> by <a href="https://screenbuddy.xyz" rel="nofollow">ScreenBuddy</a>
</p>You may remove or customize the credit line. Its links use nofollow by default. If you write about the tool separately, choose the citation and link that help your readers.
Match the canvas to your audience
Set your canvas in ScreenBuddy, choose a background and frame, and check that interface labels stay readable at the size viewers will actually watch.
Mac & Windows. Free download, no card. Record and edit free; subscribe when you need to export. Media processing stays on your device. Internet is required for account sign-in and update checks.