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Border Radius Generator

Visually generate CSS border-radius values

Reviewed: AnyCalc Editorial|2026-07-19|Editorial policy|About

What this calculator does

The CSS border-radius property allows developers to create rounded corners on HTML elements, from subtle curves to full circles and complex organic shapes. This visual generator lets you adjust each of the four corners independently, preview the result in real time, and copy the generated CSS code. You can create pill-shaped buttons, circular avatars, speech-bubble shapes, and asymmetric designs by combining different horizontal and vertical radius values. The tool supports the shorthand and longhand border-radius syntax, including the slash notation for elliptical corners. It is essential for modern UI design where sharp rectangular boxes feel outdated.

Top-Left10px
Top-Right10px
Bottom-Right10px
Bottom-Left10px
CSS Output
border-radius: 10px 10px 10px 10px;

How to use

  1. 01
    Adjust corners
    Drag sliders to set the radius for each corner individually.
  2. 02
    Preview the shape
    See real-time updates on the live preview box.
  3. 03
    Copy the CSS
    Click Copy to grab the border-radius CSS code for your project.

Border Radius Generator FAQ

How do I make a perfect circle with border-radius?▾
Set border-radius to 50% on an element with equal width and height. For example: width: 100px; height: 100px; border-radius: 50%. This creates a perfect circle regardless of the element size.
What is the slash syntax in border-radius?▾
The slash separates horizontal and vertical radii to create elliptical corners. For example, border-radius: 10px / 20px creates corners that curve 10px horizontally and 20px vertically, producing an oval-like shape rather than a circular arc.
Is border-radius supported in all browsers?▾
Yes. The border-radius property has been supported in all major browsers since IE9. Vendor prefixes like -webkit-border-radius are no longer needed for modern browser support.

Interpret carefully

Outputs are decision-support estimates, not a substitute for professional judgment.

  • Treating Border Radius Generator output as a final professional diagnosis, quote, or legal determination
  • Entering approximate values when the result is sensitive to units or precision
  • Applying the FAQ answer (“How do I make a perfect circle with border-radius?”) to a special case without checking assumptions

Next steps

  1. Double-check inputs against your source documents (labs, statements, specs, or notes).
  2. Confirm the method below matches your use case before you act on the number.
  3. For medical, financial, or production decisions, verify with a qualified professional.

Disclaimer: Results are informational only and do not constitute medical, financial, legal, or professional advice. Report issues: sublimernj@gmail.com

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