{
  "slug": "cac-payback-period",
  "title": "CAC Payback Period Calculator",
  "heading": "CAC Payback Period Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/cac-payback-period",
  "summary": "Find out how many months it takes to recoup what you spent acquiring a customer.",
  "description": "CAC payback period tells you how many months of gross margin from a customer it takes to recover the fully loaded cost of acquiring them. It's the metric that determines how much cash you tie up before a customer becomes cash-flow positive on your books, which matters enormously for how fast you can reinvest in growth without external capital. Best-in-class SaaS runs 5-12 month payback; 12-18 months is workable for enterprise motions with high ACVs and strong retention; beyond 24 months, the capital intensity of growth becomes hard to sustain without either raising more money or slowing down. Payback period and LTV:CAC measure related but distinct things — payback is about cash-flow timing and capital efficiency, while LTV:CAC is about lifetime unit economics. A company can have a great LTV:CAC ratio and still run out of cash if payback period is too long relative to its burn rate and fundraising cadence.",
  "formula": "CAC Payback (months) = CAC ÷ (Monthly Revenue per Customer × Gross Margin %)",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=cac-payback-period",
  "inputs": [
    {
      "id": "cac",
      "label": "Fully loaded CAC per customer",
      "kind": "number",
      "hint": null,
      "default": 9000,
      "unit": "$",
      "min": 1,
      "max": null
    },
    {
      "id": "acv",
      "label": "Annual contract value (ACV)",
      "kind": "number",
      "hint": null,
      "default": 18000,
      "unit": "$",
      "min": 1,
      "max": null
    },
    {
      "id": "grossMargin",
      "label": "Gross margin",
      "kind": "number",
      "hint": null,
      "default": 78,
      "unit": "%",
      "min": 1,
      "max": 100
    }
  ],
  "outputs": [
    {
      "id": "paybackMonths",
      "label": "CAC payback period",
      "format": "duration",
      "hint": null,
      "primary": true
    },
    {
      "id": "monthlyGrossProfit",
      "label": "Monthly gross profit per customer",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "annualGrossProfit",
      "label": "Annual gross profit per customer",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "cac",
      "label": "CAC used in calc",
      "format": "currency",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Fully loaded CAC per customer: 9000 $",
      "Annual contract value (ACV): 18000 $",
      "Gross margin: 78 %"
    ],
    "outputs": [
      "CAC payback period: 7.7",
      "Monthly gross profit per customer: $1,170",
      "Annual gross profit per customer: $14,040",
      "CAC used in calc: $9,000"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter fully loaded cac per customer ($).",
      "Enter annual contract value (acv) ($).",
      "Enter gross margin (%).",
      "Read your cac payback period on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "cac": 5400,
        "acv": 11000,
        "grossMargin": 47
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "cac": 9000,
        "acv": 18000,
        "grossMargin": 78
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "cac": 14400,
        "acv": 29000,
        "grossMargin": 100
      }
    }
  ],
  "limitations": [
    "Results are estimates before tax, fees, and inflation unless an input explicitly covers them.",
    "Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.",
    "This is educational maths, not financial advice. Check anything contractual with the lender or your accountant."
  ],
  "faq": [
    {
      "q": "What's considered a good CAC payback period?",
      "a": "5-12 months is excellent, typical of efficient PLG or SMB motions with fast sales cycles. 12-18 months is fine for mid-market or enterprise where deal sizes are bigger. Beyond 18-24 months, you're tying up a lot of cash per customer and need strong balance sheet or funding to sustain growth at scale."
    },
    {
      "q": "Should CAC payback use gross margin or full revenue?",
      "a": "Always use gross profit, not revenue — you can't spend the cost-of-goods-sold portion of revenue on anything, including recovering CAC. Using raw revenue overstates how fast you actually recoup acquisition spend and can mask a hosting-cost or support-cost problem hiding inside gross margin."
    },
    {
      "q": "How does payback period interact with churn?",
      "a": "If your average customer churns before payback completes, you never recover the acquisition cost at all — you lost money on that customer. Compare payback period against your average customer lifetime; payback should be comfortably shorter, ideally by 2-3x, to leave room for actual profit."
    },
    {
      "q": "What counts as fully loaded CAC?",
      "a": "All sales and marketing costs (salaries, commissions, ad spend, tools, events) divided by new customers acquired in the period — not just ad spend or commission alone. Leaving out salaries or overhead is the most common way companies understate CAC and overstate payback efficiency."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/ltv-to-cac-ratio",
    "https://www.revenuelab.fyi/toolbox/sales-magic-number",
    "https://www.revenuelab.fyi/toolbox/saas-gross-margin"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — CAC Payback Period Calculator (https://www.revenuelab.fyi/toolbox/cac-payback-period)"
}