How the Funnel Leak Finder calculates the “biggest leak”

This tool turns your funnel into three step‑by‑step conversions: Stage 1 → 2, Stage 2 → 3, and Stage 3 → 4. Each step has a conversion rate and a drop‑off count. Then we estimate the upside of improving one step by your chosen Fix‑the‑leak boost (for example, +20% relative improvement).

For each step, conversion rate is: CR = Next Stage Volume ÷ Previous Stage Volume. If Stage 2 = 700 and Stage 1 = 10,000, then CR₁₂ = 700/10,000 = 0.07 = 7%.

Drop‑off count is: Drop = Previous Stage Volume − Next Stage Volume. In the same example: 10,000 − 700 = 9,300 users lost at Step 1 → 2.

We treat Stage 4 as “purchases” (or paid conversions). Revenue is: Revenue = Purchases × Value per purchase. Gross profit is: Gross Profit = Revenue × Gross Margin.

A “boost” is a relative improvement to the conversion rate of one step. If a step converts at 10% and you choose a +20% boost, the new rate becomes: 10% × (1 + 0.20) = 12%. We cap rates at 100%. Then we flow that improvement downstream while keeping later conversion rates the same — which helps you estimate how many extra final purchases you’d get if you fixed that one leak only.

3 quick examples you can copy

• SaaS: 10,000 visits → 700 leads → 210 trials → 63 paid. Biggest revenue leak is often Trial → Paid because it’s closest to revenue.
• E‑commerce: 50,000 visits → 2,000 add‑to‑carts → 900 checkouts → 540 purchases. Biggest rate leak might be Cart → Checkout; fix with shipping clarity and fewer steps.
• Lead gen: 100,000 impressions → 2,500 clicks → 500 leads → 40 customers. Biggest volume leak might be Impressions → Clicks; fix with better creative and targeting.

Notice the pattern: “biggest leak” changes depending on where the volume is and where revenue leverage is. The calculator shows all three perspectives so you can pick the best experiment.

A simple funnel‑fixing workflow (that actually ships)

Most funnels don’t need 20 tweaks — they need one strong fix, measured properly. Use this workflow to turn the calculator into action:

• Pick a period where your numbers are stable (week/month).
• Use totals from analytics, CRM, or your dashboard.
• Don’t worry if numbers aren’t perfect — direction is the goal.

• The tool estimates which step improvement yields the largest extra purchases.
• That step becomes your experiment backlog focus for the week.

• Pick one hypothesis (e.g., “fewer form fields increases lead conversion”).
• Ship a change: new page section, shorter form, better CTA, onboarding checklist, checkout trust signals.
• Measure the same step conversion rate for the next period.

• Update volumes after the experiment window.
• If the leak moved, congrats — you fixed something. Now repeat.

Frequently Asked Questions

• What if my funnel has more than 4 stages?

  Use the 4 stages that matter most for decision‑making. For example: Visits → Leads → Activated → Paid. Or compress multiple steps into one stage (“Activated” could mean “completed onboarding + used feature X”).

• Why do you model a “relative” boost instead of adding points?

  Relative lifts match how growth teams talk about improvements (e.g., “+15% on conversion rate”). It also scales naturally across high and low baselines.

• Will improving one step always increase purchases?

  Not always. Downstream capacity, lead quality, seasonality, and product constraints matter. Treat the estimate as a planning tool — then validate with real experiments.

• Should I always fix the lowest conversion rate step?

  Not necessarily. A low conversion rate early in the funnel might still produce plenty of volume. Often the best “ROI” comes from improving a later step that is closer to revenue.

• What does “gross margin” do here?

  It helps translate extra purchases into approximate gross profit. If your margin is 70%, then every $100 in extra revenue implies ~$70 in gross profit (before marketing and overhead).

• Can I share or save results?

  Yes. Use the share buttons to generate a quick message with your key metrics, and “Save” to store snapshots locally in your browser.

Turn this into a shareable “leak scorecard”

The fastest way to make this tool go viral is to turn the output into something people can post: a before → after snapshot with one clear recommendation. Use the Copy button after you calculate to share:

• Your overall funnel conversion (%)
• Your biggest leak step
• Your projected upside from a realistic boost

Bonus: Run it for two different periods (last month vs this month) and share the trend. People love “what changed?”