If you're building a product, there's one milestone that changes everything: Product-Market Fit (PMF). It’s the moment your product truly resonates with your market—when users not only adopt but stick around, pay for it, and even advocate for it.

But while PMF feels magical, it's not some vague, unmeasurable idea. The smartest founders and product teams use data and behavioral patterns to know when they’ve reached it. So, how can you measure it meaningfully?

Let’s break down what the experts say.

1. The Core Metrics That Signal PMF

Enzo Avigo (CEO of June) categorizes PMF into three clear tiers based on quantitative and qualitative indicators:

‍No PMF<10% user research acceptance, <1% website conversion, <50 active users, <20% retention at 6 months

‍Some PMF>20% user research acceptance, >2% website conversion, some paying users, 3% weekly growth

‍Strong PMF40%+ users would be “very disappointed” if product disappeared, 5–10% WoW growth, >40% 6-month retention

That “very disappointed” metric has become a cult favorite. Ask your users, “How would you feel if you could no longer use this product?” If 40% or more say they’d be very disappointed, that’s a green light.

2. Focus on Retention Over Vanity Metrics

Forget sign-ups and website visits. Gustaf Alströmer (ex-Airbnb) argues that retention is the most reliable indicator of PMF.

Why? Because people returning consistently shows they’re getting real value.

A Few Benchmarks:

• Airbnb: Measured retention annually—people book once a year.
• Lyft: Focused on rider frequency—measured weekly/monthly.
• DoorDash: 30% retention at 2 months, 21% at 20 months = PMF.
• GitHub: 80% 1-month retention, 30% after 60 months = PMF and stickiness.

Pro Tip: Plot your retention cohorts over time. If the graph flattens (instead of trending toward zero), you're likely on the right track.

3. Revenue & Behavior: Let Your Data Speak

Peter Reinhardt, co-founder of Segment, emphasizes revenue acceleration after launching a new feature as a powerful signal of PMF. Seeing a clear upward shift in your revenue trend can show that you’ve delivered something people truly value.

Tom Blomfield (Monzo) suggests watching these 3 metrics early on:

• Returning usage/retention
• Net Promoter Score (aim for >50)
• Paying customer renewal rate

However, Gustaf warns: don’t rely solely on NPS. Instead, measure behavioral engagement—how often and how deeply users interact with your product.

4. Tailoring Metrics to Your Product

Not all PMF metrics are created equal. Your product’s context defines what matters most.

Mixpanel recommends a layered metric approach:

• Level 1 (L1): Direct contributors to your North Star (e.g., 7-day retention)
• Level 2: Channel- or feature-specific metrics (e.g., mobile retention)
• Level 3: Regional, persona-based, or granular data (e.g., iOS retention in Europe)

Avoid metric overload. Choose a few metrics that tie directly to value, not just activity.

5. PMF ≠ Perfection. It’s a Direction.

One final reminder: PMF isn’t about perfect scores. It’s about clear signals that your product is resonating deeply with a segment of your audience.

Strong retention. Emotional attachment. Willingness to pay. Organic growth. These are your north stars.

Summary: The Metrics That Matter Most

Here’s your quick PMF measurement checklist:

✅ 40%+ of users say they’d be very disappointed if you disappeared
✅ Retention curve flattens—users stick around
✅ 5–10% WoW active user growth
✅ 6-month retention > 40%
✅ People are paying—and renewing
✅ Revenue grows post-feature launches
✅ Metrics align with your product’s usage frequency