After 7+ years in product design, I’ve seen designers obsess over the wrong metrics.

They track everything: time on page, scroll depth, click rates, heat maps, and dozens of other data points.

Yet when the CEO asks how their work moves the business forward, they freeze.

Here’s the truth: You only need 5 metrics to prove your design’s value and become indispensable to any company.

Not 20. Not 10. Just 5.

Let me show you which ones actually matter and why most of what you’re tracking is just noise.

Why Most Design Metrics Are Bullshit

Most metrics designers track are vanity metrics. They make us feel good in design critiques but don’t actually prove our work drives business value.

Time on page? Could mean your UI is confusing.

Scroll depth? Means nothing if users don’t take action.

Page views? Worthless if they don’t convert.

Even worse, tracking too many metrics leads to analysis paralysis. You end up with beautiful dashboards that don’t tell you what to do next.

Meanwhile, founders and executives are looking at completely different numbers. No wonder designers struggle to get a seat at the table.

Are you reading this but your startup, company or product has no metrics yet measured? No analytics?

Then it is time to start! Tell your team you need to install Google Analytics or PostHog to track the 5 metrics you see below. The reason is you want to start tracking those metrics so devs can stop developing useless features and you can start making data-supported decisions.

The Only 5 Metrics That Actually Matter

After working with startups and established companies like Upwork, Deltia & Prosp AI, I’ve identified the only five metrics designers need to track.

These metrics:

1. Directly impact business growth
2. Can be influenced by design decisions
3. Speak the language of executives and investors

Let’s break them down.

Metric #1: Retention Rate

If you track just one metric, make it retention.

Why? Because keeping existing users is cheaper than acquiring new ones. And retention is the clearest sign your product actually solves a problem.

How to measure it: The percentage of users who return to your product after their first visit within a specific timeframe. For SaaS, look at 30/60/90-day retention. For consumer apps, daily/weekly active users matter more.

How design impacts retention:

• Reducing friction in core workflows
• Creating habit-forming triggers
• Making key features more discoverable
• Reducing cognitive load

Industry example: When Slack redesigned their mobile experience, they focused specifically on returning users rather than first-time users. The result? Their daily active users increased substantially because the redesign made it easier for people to stay in the loop with fewer taps.

Pro tip: Break down retention by user segment and acquisition channel. Design differently for different user types.

Metric #2: Conversion Rate

This isn’t just for e-commerce or landing pages.

Every product has critical conversion points: Trial to paid. Free to premium. Signup to activation. Adding the first project. Inviting team members.

How to measure it: The percentage of users who complete a desired action divided by total visitors/users who could take that action.

Here are some common benchmarks for conversion rates: https://userpilot.com/blog/b2b-saas-funnel-conversion-benchmarks/

How design impacts conversion:

• Clearer calls-to-action
• Reduced form fields
• Better information hierarchy
• Strategic use of social proof
• Smarter default settings

Industry example: Dropbox famously increased conversion by 10% by simply shortening their signup form and clarifying the value proposition on their homepage. No fancy animations or groundbreaking visual design—just clearer communication.

Pro tip: Don’t just track the overall conversion rate. Track each step in your funnel to find exactly where users drop off.

Metric #3: Time to Value

How quickly can users experience the core value of your product?

This is the most underrated metric in product design.

The faster users reach their “aha moment,” the more likely they are to stick around and pay you money.

How to measure it: Time or number of steps required for a new user to experience your product’s core value proposition.

How design impacts time to value:

• Shorter onboarding
• A clear user journey
• Remove everything but the “aha moment”
• Social Logins (don’t waste time here)

Industry example: Twitter recognized their “aha moment” happened when new users followed at least 10 accounts. By redesigning their onboarding to focus specifically on helping users reach that milestone faster, they dramatically improved retention.

Pro tip: Map your entire user journey and identify exactly when users first experience your product’s core value. Then work relentlessly to move that moment earlier.

Metric #4: Net Promoter Score (NPS)

Yes, NPS has flaws. But it remains the simplest way to measure user satisfaction and predict growth.

The key is looking beyond the score itself to the qualitative feedback.

How to measure it: “On a scale from 0-10, how likely are you to recommend our product to others?” (followed by “Why did you give this score?”)

How design impacts NPS:

• Solving core user problems
• Creating memorable moments (make it 1% more fun)
• Make sure to deliver value even after 30 days
• Eliminating frustration

Industry example: When Airbnb noticed their NPS scores dropping, they found the issue wasn’t with their core booking experience but with their search and discovery flows. By redesigning how users find and filter places, they improved satisfaction scores significantly.

Pro tip: Segment your NPS by user type, plan type, and usage frequency. Design improvements for your most valuable segments first.

Metric #5: Revenue Per User

This is where everything comes together.

Revenue per user (sometimes called ARPU or average revenue per user) is the ultimate business metric that ties your design work directly to the bottom line.

How to measure it: Total revenue divided by total number of users in a given time period. For subscription businesses, look at MRR (monthly recurring revenue) per user.

How design impacts revenue per user:

• More intuitive upsell paths
• Better feature discovery for premium features
• Clearer communication of value
• Strategic friction reduction for payment flows
• Focus on collaboration features

Industry example: Spotify continuously experiments with their premium upgrade experience, testing different messaging, timing, and visuals. Their focus on optimizing this conversion path is a key reason their revenue per free user has increased year over year.

Pro tip: Track revenue per user over the customer lifetime, not just in a single month. This reveals the long-term impact of your design decisions.

How to Actually Use These Metrics

Knowing what to track is just the beginning. Here’s how to use these metrics to drive your design decisions:

1. Create a simple dashboard with just these 5 metrics (I personally track this in a Google Sheet)
2. Set clear targets for each metric before starting design work
3. Measure the baseline before making changes
4. Run controlled experiments to isolate the impact of design changes
5. Present results in business terms, not just design terms

Most importantly, focus on one metric at a time. You can’t optimize for everything at once.

The Hard Truth About Metrics

Let me be brutally honest: If your design work isn’t moving these five metrics, you’re just making things pretty.

That might win design awards, but it won’t advance your career or help the business grow.

The best designers I know don’t just create beautiful interfaces. They solve business problems through design.

They speak the language of metrics. They understand how their work impacts the bottom line. And they’re not afraid to be measured by the results they deliver.

Final Call To Action:

Ask yourself: Which of these five metrics would have the biggest impact on your product if you improved it by 20%?

A prompt you can use:

You are Head of Product for a tech scaleup, with over 20 years of experience in buildings successful products and set up KPIs and product roadmaps. You follow Lenny Rachitsky to learn even more about product management.

I want to start tracking my most important KPIs for our product, so I can improve the design and user experience.

The most important KPIs are:

1. Retention Rate
2. Conversion Rate
3. Time to Value
4. NPS Score
5. Revenue per Customer

Please share in a short and precise way, using simple words, why the following metrics matter, and how to start measuring them.

After that, ask me to input some key metrics for the last 30 days, so that you can calculate the current benchmark for those metrics for my product.

After my input, give me suggestions for what to work on in my product, because you know best what design change has the biggest impact on my KPIs.

For context: I’m a designer for a legal tech startup, and we are building a new way to review contract using AI for lawyers. We currently have about 5 customers with 48 total users.