The border-end-end-radius property rounds the logical end-end corner of an element — where the block-end edge meets the inline-end edge. It is ideal for layouts that must work in both LTR and RTL text directions.
01
Logical Corner
End-end, not physical.
02
Length Values
px, em, rem.
03
Percentages
Relative to box size.
04
Elliptical
Two-value syntax.
05
RTL Ready
Adapts to direction.
06
Logical Family
Part of border-radius.
Fundamentals
Definition and Usage
The border-end-end-radius CSS property controls the rounding of the logical end-end corner of an element’s border box. This corner sits at the intersection of the block-end side and the inline-end side.
In standard left-to-right horizontal writing, end-end usually maps to the bottom-right corner. In right-to-left layouts, the same property rounds the bottom-left corner instead — without changing your CSS. That makes it especially useful for multilingual and bidirectional designs.
💡
Beginner Tip
Think of end-end as “the far corner on the ending side.” Start with border-end-end-radius: 20px; on a colored box and compare it in both direction: ltr; and direction: rtl;.
Foundation
📝 Syntax
The syntax for border-end-end-radius lets you use one value for a circular corner or two values for an elliptical corner:
The default value of border-end-end-radius is 0. That means the end-end corner is not rounded unless you set a radius value.
Reference
💎 Property Values
border-end-end-radius accepts length, percentage, and elliptical values.
Value
Example
Meaning
Length
border-end-end-radius: 20px;
Fixed corner radius such as px, em, or rem
Percentage
border-end-end-radius: 50%;
Radius relative to the element’s dimensions
Elliptical
border-end-end-radius: 40px / 10px;
Different horizontal and vertical radii
initial
border-end-end-radius: initial;
Resets to the default value of 0
inherit
border-end-end-radius: inherit;
Inherits the value from the parent element
unset
border-end-end-radius: unset;
Resets to inherited or initial value depending on context
10px20px50%
Common Value Types
fixed px
percentage
elliptical
Scope
Logical End-End Corner and Writing Modes
border-end-end-radius follows the inline and block axes instead of fixed top, right, bottom, and left sides. In horizontal LTR text, end-end is usually the bottom-right corner. In RTL, the same rule rounds the bottom-left corner.
LTR (direction: ltr)
end-end corner
start-startend-startstart-endend-end
RTL (direction: rtl)
end-end corner
end-startstart-startend-endstart-end
Square corner (default)
Rounded end-end
Compare
border-end-end-radius vs related properties
Property
Targets
Best for
border-end-end-radius
Logical end-end corner
Multilingual, RTL, and writing-mode-aware layouts
border-bottom-right-radius
Physical bottom-right corner
Simple LTR-only layouts with one rounded corner
border-end-start-radius
Logical end-start corner
The opposite end corner on the same block edge
border-radius
All four corners together
Cards, buttons, and fully rounded boxes
Preview
👀 Live Preview
A box with a rounded logical end-end corner in LTR layout:
Uses width: 10rem;, height: 6rem;, background: #2563eb;, and border-end-end-radius: 20px;.
Hands-On
Examples Gallery
Try border-end-end-radius with fixed lengths, percentages, elliptical corners, and RTL-friendly cards.
📚 Basic Corner Rounding
Start with a single length value to round the logical end-end corner of a box.
Example 1 — 20px End-End Radius
Create a block with a rounded end-end corner using a fixed pixel value, as shown in the reference tutorial.
border-end-end-radius-basic.html
<style>.rounded-corner{border:2px solid #000;border-end-end-radius:20px;padding:20px;width:200px;height:100px;background-color:#f0f0f0;}</style><divclass="rounded-corner">
This block has a rounded end-end corner.
</div>
Because border-end-end-radius is logical, the rounded corner stays on the trailing end of the block edge in both LTR and RTL. You do not need separate left and right radius rules.
🧠 How border-end-end-radius Works
1
You choose a radius value
Set a length, percentage, or elliptical value with border-end-end-radius.
CSS rule
2
The browser finds the logical corner
It maps end-end to the correct physical corner based on writing mode and text direction.
Logical mapping
3
The corner is curved
Only the end-end corner gets a rounded arc. The other three corners stay unchanged.
One corner
=
◯
Direction-aware rounded corner
Your layout keeps the same CSS while the rounded corner follows the logical end of the box.
Compatibility
Modern Browser Support
The border-end-end-radius property is supported in modern browsers that implement CSS Logical Properties. Test in the browsers your audience uses, especially for RTL layouts.
✓ Baseline · Modern browsers
Logical corner rounding in today’s browsers
Chrome, Edge, Firefox, and Safari support border-end-end-radius in current versions.
92%Modern browser support
Google Chrome89+ · Desktop & Mobile
Full support
Mozilla Firefox66+ · Desktop & Mobile
Full support
Apple Safari15+ · macOS & iOS
Full support
Microsoft Edge89+ · Chromium
Full support
Opera76+ · Modern versions
Full support
Fallback behavior
When unsupported, the corner stays square. Use physical longhands only if you must support very old browsers.
💻
Internet ExplorerNo support · Use border-bottom-right-radius as fallback
None
border-end-end-radius property92% supported
Bottom line: Use border-end-end-radius for modern multilingual layouts. Pair with physical fallbacks only when legacy browser support is required.
Wrap Up
Conclusion
The border-end-end-radius property gives you precise control over one logical corner while keeping your CSS adaptable across text directions and writing modes. It is a strong choice for bidirectional layouts where a physical bottom-right rule would break in RTL.
Experiment with pixel values, percentages, and elliptical syntax to see how this property can enhance the visual appeal and flexibility of your web projects.
Use logical radius properties in multilingual or RTL interfaces
Start with small radius values and increase gradually
Combine with overflow: hidden when clipping inner content to the curve
Test the same component in both LTR and RTL
Prefer logical corners when building reusable layout components
❌ Don’t
Use physical corner properties when logical ones would stay correct in RTL
Assume percentage radii behave like fixed pixel values
Forget that writing mode can change which physical corner is affected
Mix too many different corner radii in one small UI without a clear design reason
Skip browser testing for direction-aware layouts
Summary
Key Takeaways
Knowledge Unlocked
Five things to remember about border-end-end-radius
Use these points when rounding the logical end-end corner.
5
Core concepts
◯01
Logical Corner
End-end, not fixed side.
Purpose
⚡02
Default 0
Square corner.
Default
📏03
px or %
Fixed or relative.
Values
🖼️04
RTL Ready
Adapts to direction.
Logical
🛠05
Longhand
Part of border-radius.
Family
❓ Frequently Asked Questions
The border-end-end-radius property rounds the logical end-end corner of an element — the corner where the block-end edge meets the inline-end edge. In left-to-right horizontal text, that is usually the bottom-right corner.
The initial value is 0, which means the end-end corner is square with no rounding.
border-bottom-right-radius always targets the physical bottom-right corner. border-end-end-radius follows writing direction and writing mode, so the same rule can stay correct in RTL or vertical layouts.
Yes. Percentage values are calculated relative to the element's width and height, so the same percentage can produce different curves on different box sizes.
Use it when you want one rounded corner that adapts to text direction or writing mode, such as in multilingual sites, RTL interfaces, or logical layout systems.