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CAC Payback & LTV:CAC Calculator

CAC and LTV get thrown around constantly, but most teams eyeball them rather than calculate them properly — and a CAC that ignores fully-loaded S&M spend, or an LTV that ignores gross margin, will flatter numbers that don't survive board scrutiny. This calculator uses the same subscription-economics formulas investors use: gross-margin-adjusted LTV, a churn-derived customer lifetime, and a payback period benchmarked against the 12-month standard for efficient SaaS and B2B growth. Enter your spend, customer, revenue, margin, and churn numbers below to see where you actually stand.

Your numbers

Fully loaded: salaries, commissions, tools, ad spend, overhead — same period as customers below
In the same period as the spend above
Average annual contract value across your customer base
Revenue minus the cost of delivering the product/service
% of customers lost per year — lower churn means longer customer lifetime and higher LTV

Method & assumptions

  • LTV = (annual revenue per customer × gross margin) ÷ annual churn rate — the standard subscription-economics formula used in SaaS/B2B investor reporting.
  • CAC payback period = CAC ÷ monthly gross profit per customer. Under 12 months is the widely-used benchmark for efficient venture-backed SaaS; longer can still be healthy for capital-efficient or enterprise motions with long contract terms.
  • 3:1 is treated as the minimum sustainable LTV:CAC ratio, with 3–5:1 as the healthy range. Ratios far above 5:1 aren't necessarily a problem, but can indicate under-investment in growth rather than pure efficiency.
  • "Total S&M spend" should be fully loaded — reps' OTE and commissions, marketing headcount, tools and ad spend, and a fair share of overhead. A partial number will understate CAC and overstate every ratio built on it.

How to use it

Enter total fully-loaded Sales & Marketing spend and the number of new customers acquired in that same period — the tool divides these to get CAC. Then enter average annual revenue per customer, gross margin %, and annual churn rate — it uses these to derive LTV (gross-margin-adjusted, divided by churn) and the CAC payback period (CAC divided by monthly gross profit per customer). The output shows all four headline metrics, bar comparisons against standard benchmarks, a status table, and a verdict with specific recommendations for whichever metric is weak.

For enablement leaders

Make the layer underneath this measurable.

Tools like this describe good practice. They can't tell you which of your reps actually have the skill, or in what order to build it. That's what The Mastery Standard does: 27 frameworks, 54 competencies, every rubric cell written, every assessment human-signed-off.

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