Why Rounded Corners 
Are Everywhere in Design

Why Rounded Corners 
Are Everywhere in Design

Rounded corners are all around us, from software interfaces to the design of devices. There's just something about rounded corners that's visually pleasing. They've been used so much by designers that they've become more of an industry norm than just a passing design fad. But what makes rounded corners so widely liked and used?

Less irritating to the eyes

Research has indicated that rectangles with rounded corners are less visually irritating compared to sharp-edged rectangles. This is because they require less cognitive effort to process visually. The central fovea on the retina processes circular shapes more efficiently. Processing the edges of an object involves more neural resources in the brain. As a result, rectangles with rounded corners are more user-friendly because they resemble circles, which are easier to work with compared to standard rectangular shapes.

Additionally, scientific studies conducted by the Barrow Neurological Institute have shown that the perceived prominence of an angle is directly related to the angle's sharpness. Sharper angles appear more prominent, and the brighter a corner appears, the more challenging it is to look at.

Our instinctual "avoidance response" to sharp corners, ingrained from an early age, encourages us to steer clear of potentially dangerous or sharp objects in the physical world. As a result, we tend to prefer rounded and organic shapes, which we perceive as safer. This response, studied by neuroscientists, highlights how our brains prioritize safety and contribute to our preference for rounded corners in design.

Easier to process

Rounded corners are more effective for maps and charts because they facilitate smoother line tracking. Unlike sharp corners that can disrupt the line's flow and lead to abrupt pauses when it changes direction, rounded corners allow our gaze to seamlessly follow the path of the line without interruptions.

Rounded corners are also effective as content containers. This is because the curvature of rounded corners directs the attention inwards toward the center of the rectangle, highlighting the content within. Furthermore, when two rectangles are positioned side by side, it's easy to distinguish which side belongs to each rectangle.

On the other hand, sharp corners direct attention outwards, diminishing the focus on the content inside the rectangle. They also make it challenging to discern which side corresponds to each rectangle when they are adjacent. This confusion arises because every side of a rectangle with sharp corners is a straight line, whereas the rounded corners of a rectangle offer a unique visual cue by curving inwards toward their respective rectangle.

Problems with rounding

After thinking it through, one might be tempted to use rounded corners everywhere! However, this isn't always the optimal choice. When designing a product, we should consider its purpose and objectives to ensure it's perceived correctly by users. While rounding a single corner may not seem significant on its own, applying this design approach extensively, such as across an entire interface, can profoundly transform a product's appearance.

The core concept here is that individuals tend to recall the first and last items in a sequence more effectively compared to those in the middle.

Square shapes are often associated with reliability, uniformity, tradition, and professionalism.

Round shapes tend to convey charisma, attraction, approachability, and friendliness.

Triangular shapes are typically linked to dynamism, energy, and power.

Hence, when creating a design, it's crucial to consider the objectives of our brand or product, as the shapes we select for key design elements can significantly influence how users perceive them. Using rounded corners may be fitting if we aim for a friendly and innocent look, but it's not a one-size-fits-all solution.

In conclusion

There are undoubtedly valid reasons why we appreciate rounded corners in both physical and digital products. This affinity for roundness is deeply ingrained in our upbringing, stemming from the prevalence of round shapes in the natural world.

Nonetheless, as we've learned, this doesn't imply that we should indiscriminately employ rounded corners in our designs. Various shapes elicit distinct reactions from users, and rounding corners can lead to unintended perceptions that impact the overall user experience. When designing interfaces, it's essential to diversify shapes to direct users toward the right actions and convey the interface's hierarchy effectively.