Why a designer needs to talk in numbers?
Laws/principles vs numbers
Early in my career, I used to explain design decisions using classic UX principles and law such as Hick’s Law, Fitts’ Law, cognitive load, and all those concepts we love. But I quickly realized something: business teams and senior people in my org didn’t care about laws; they care about results. 💰
Decisions that convince
Imagine this: You propose a new checkout flow, saying, "This reduces cognitive load and aligns with best UX practices." Sounds solid, right? But now compare it to: "This change will reduce drop-off rates by 18%, increasing conversions and bringing in an estimated $200K in revenue per quarter."
Which one do you think gets immediate buy-in? The second one. Because business leaders speak in numbers, not in heuristics.
An example
Amazon’s legendary one-click checkout wasn’t pitched with just laws. It was backed by metrics. They showed that removing extra steps reduced cart abandonment and increased repeat purchases. The result? Billions in revenue growth and a patented checkout process that gave them a competitive edge.
Numbers build trust
When you back your design decisions with numbers, conversions, retention metrics, engagement rates, or revenue impact, you make your work more than just a simple creative choice—it becomes a business strategy.
Laws and principles helps to create intuitive experiences, but data proves the value in real-world impact. A smoother checkout flow isn’t just “better for usability”—it reduces friction, leading to lower drop-off rates and higher transaction completions. A well-placed CTA isn’t just “visually prominent”—it improves click-through rates and drives user action.
If the designers want a stronger voice in business discussions, we need to slowdown explaining designs only in terms of “good experience” and start demonstrating how better experiences lead to measurable success. Speaking in numbers builds trust, aligns us with company goals, and ultimately makes UX a key driver of growth, not just an aesthetic improvement.
