Growth tool

What a customer costs, and what they return.

Acquisition cost against lifetime value, with the payback period that decides whether you can afford to grow quickly or have to grow out of cash flow.

  • Free, no sign-up
  • LTV:CAC ratio
  • Payback in months

CAC and LTV calculator

Free
Over the period you are measuring.
80.00CAC
864.00LTV — gross profit
10.8:1LTV to CAC
3.3Payback, months
1,440.00Lifetime revenue
72.00Gross profit, first order
784.00Net value per customer
12.0Lifetime orders
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Worth knowing

The two numbers that decide growth.

  1. 01

    Put LTV in gross profit, never in revenue

    A customer who spends $1,440 over three years at a 60% margin is worth $864 to you, not $1,440. Comparing revenue-based LTV against CAC is the most common way a business convinces itself that unprofitable acquisition is working. This calculator applies margin for exactly that reason.

  2. 02

    The 3:1 rule is a rule of thumb, not a law

    Below roughly 3:1 you are usually buying growth at a loss once overheads are counted. Far above it — 8:1, 10:1 — often means the opposite problem: you are under-investing and leaving reachable customers to competitors. A very high ratio is a prompt to spend more, not a trophy.

  3. 03

    Payback period is the number that governs cash

    Ratio tells you whether the model works eventually; payback tells you whether you can survive the wait. Recovering CAC in one month lets you reinvest almost immediately. Eighteen months means you need financing to grow at all, however healthy the ratio looks.

Questions

About this tool.

CAC = total sales and marketing spend ÷ new customers acquired in the same period. Include ad spend, agency fees, sales salaries and commissions — not just media cost, or the figure flatters itself.
Average order value × orders per year × years retained × gross margin. That gives lifetime gross profit, which is the figure that can honestly be set against CAC.
Around 3:1 is the widely used benchmark for a sustainable model. Under 3:1 suggests acquisition is too expensive or retention too weak; well above it often signals under-investment in growth.
Under 12 months is generally considered healthy for subscription businesses, and ecommerce usually wants far less — ideally recovering CAC on the first or second order. The shorter it is, the less external funding growth requires.

Growth that funds itself.

We build acquisition and retention around the payback period, not the vanity metric.

Free scope, fixed price.We reply within one business day.

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