{
  "slug": "churn-rate",
  "title": "Churn Rate Calculator",
  "heading": "Churn Rate Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/churn-rate",
  "summary": "Customer churn, revenue churn, and retention.",
  "description": "Logo churn counts customers; revenue churn counts dollars. When expansion revenue from existing accounts exceeds what churns, net revenue retention goes above 100% and the business grows without adding a single customer.",
  "formula": "Churn = Lost ÷ Starting count. NRR = (Start + Expansion − Churned) ÷ Start.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=churn-rate",
  "inputs": [
    {
      "id": "start",
      "label": "Customers at start of month",
      "kind": "number",
      "hint": null,
      "default": 840,
      "unit": null,
      "min": 1,
      "max": null
    },
    {
      "id": "lost",
      "label": "Customers lost",
      "kind": "number",
      "hint": null,
      "default": 29,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "startMrr",
      "label": "Starting MRR",
      "kind": "number",
      "hint": null,
      "default": 74000,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "lostMrr",
      "label": "MRR churned",
      "kind": "number",
      "hint": null,
      "default": 2100,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "expansionMrr",
      "label": "Expansion MRR",
      "kind": "number",
      "hint": null,
      "default": 3400,
      "unit": "$",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "churn",
      "label": "Monthly customer churn",
      "format": "percent",
      "hint": null,
      "primary": true
    },
    {
      "id": "annualChurn",
      "label": "Annualised churn",
      "format": "percent",
      "hint": null,
      "primary": false
    },
    {
      "id": "revenueChurn",
      "label": "Gross revenue churn",
      "format": "percent",
      "hint": null,
      "primary": false
    },
    {
      "id": "nrr",
      "label": "Net revenue retention",
      "format": "percent",
      "hint": null,
      "primary": false
    },
    {
      "id": "retention",
      "label": "Monthly retention",
      "format": "percent",
      "hint": null,
      "primary": false
    },
    {
      "id": "lifespan",
      "label": "Average lifespan (months)",
      "format": "decimal",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Customers at start of month: 840",
      "Customers lost: 29",
      "Starting MRR: 74000 $",
      "MRR churned: 2100 $",
      "Expansion MRR: 3400 $"
    ],
    "outputs": [
      "Monthly customer churn: 3.45%",
      "Annualised churn: 34.4%",
      "Gross revenue churn: 2.84%",
      "Net revenue retention: 101.8%",
      "Monthly retention: 96.55%",
      "Average lifespan (months): 29"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter customers at start of month.",
      "Enter customers lost.",
      "Enter starting mrr ($).",
      "Enter mrr churned ($).",
      "Enter expansion mrr ($).",
      "Read your monthly customer churn 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": {
        "start": 500,
        "lost": 17,
        "startMrr": 44000,
        "lostMrr": 1300,
        "expansionMrr": 2000
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "start": 840,
        "lost": 29,
        "startMrr": 74000,
        "lostMrr": 2100,
        "expansionMrr": 3400
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "start": 1340,
        "lost": 46,
        "startMrr": 118000,
        "lostMrr": 3400,
        "expansionMrr": 5400
      }
    }
  ],
  "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": "How does the churn rate calculator work?",
      "a": "Logo churn counts customers; revenue churn counts dollars. When expansion revenue from existing accounts exceeds what churns, net revenue retention goes above 100% and the business grows without adding a single customer. The underlying maths is: Churn = Lost ÷ Starting count. NRR = (Start + Expansion − Churned) ÷ Start."
    },
    {
      "q": "What do I need to enter?",
      "a": "5 values: customers at start of month, customers lost, starting mrr, mrr churned, and expansion mrr. Each field starts with a sensible default, so you can change one number at a time and watch the result move."
    },
    {
      "q": "What does the monthly customer churn result mean?",
      "a": "It is returned as a percentage and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds."
    },
    {
      "q": "Is this calculator free, and do I need an account?",
      "a": "Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser."
    },
    {
      "q": "How accurate is the result?",
      "a": "It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them."
    },
    {
      "q": "Who is this tool for?",
      "a": "It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/ltv",
    "https://www.revenuelab.fyi/toolbox/mrr-growth",
    "https://www.revenuelab.fyi/toolbox/cac"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Churn Rate Calculator (https://www.revenuelab.fyi/toolbox/churn-rate)"
}