What Is Miller’s Law?

What is Miller’s Law?

Miller’s Law is a cognitive psychology principle introduced by George A. Miller in 1956. It states that the average person can hold about 7 (plus or minus 2) items in their working memory at any given time.

So, whether it's remembering a short list of words, digits, or concepts, most people can only juggle 5 to 9 pieces of information before their brain starts to drop the ball.

This limitation is a big deal in UI/UX design, where overwhelming users with too much information can lead to confusion, frustration, or abandonment.

Why Miller’s Law matters in design

Understanding Miller’s Law helps us respect cognitive load—the mental effort required to process and understand information.

When designers ignore these limits, users are forced to:

• Overthink navigation choices

• Lose track of their place in a process

• Forget important form fields or instructions

• Abandon tasks halfway

Applying Miller’s Law isn’t about limiting content—it’s about organizing it better so users can absorb and interact with it efficiently.

Practical applications of Miller’s Law in UI/UX design

1. Group information into chunks

Chunking is the go-to technique when applying Miller’s Law. Instead of overwhelming users with one long list, break it into smaller, meaningful groups.

Examples:

• Grouping 10+ items into 3–4 categories

• Formatting long numbers like credit cards (e.g., 1234 5678 9012 3456)

• Using cards or sections to split content

2. Simplify navigation menus

Avoid stuffing your menu with 10+ items. Stick to fewer options, or organize them into subcategories. This improves scanning and decision-making.

Tip: If your navigation bar has more than 7 items, it’s time to rethink your IA (information architecture).

3. Limit options in forms and settings

Whether it’s a dropdown list or a settings panel, don’t make users scroll through endless choices. Show the most relevant options first, and use progressive disclosure for the rest.

4. Design step-by-step processes

Onboarding flows, checkout processes, or survey forms? Break them into manageable steps. People feel more confident when they only have to process a few things at a time.

5. Avoid visual clutter

Too many elements on a screen at once? Users can’t focus. Respect Miller’s Law by reducing non-essential content and sticking to a clear visual hierarchy.

Common misunderstandings

Some people think Miller’s Law means you should never display more than 7 items. That’s not the case. It’s a guideline, not a hard limit. What matters is how well the content is organized and how cognitively demanding the task is.

With good chunking and visual design, you can display more information without overwhelming users.

In summary

So, what is Miller’s Law? It’s a simple reminder that our short-term memory has limits—and respecting those limits leads to better, cleaner, and more human-centered design. Whether you're creating navigation menus, breaking down complex forms, or structuring content, keeping this principle in mind will help you create experiences that feel intuitive instead of overwhelming.