{
    "name": "Customer Retention Rate Calculator",
    "url": "https://calculators.geekmidst.com/calculators/customer-retention-rate-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/customer-retention-rate-calculator.md",
    "category": "Commerce & retail",
    "description": "Calculate customer retention rate from customers at the start and end of a period and new customers gained, with churn and customers lost.",
    "summary": "Retention rate is the share of the customers you started with who are still customers at the end. New customers are subtracted first so growth does not hide losses.",
    "also_called": [
        "CRR calculator",
        "Retention rate calculator"
    ],
    "applies_to": "Worldwide",
    "last_updated": "2026-10-29",
    "computation": "Results are computed in the visitor’s browser on the HTML page. This API describes the calculator; it does not compute results.",
    "inputs": [
        {
            "name": "start_customers",
            "label": "Customers at the start (S)",
            "type": "number",
            "default": "1000"
        },
        {
            "name": "end_customers",
            "label": "Customers at the end (E)",
            "type": "number",
            "default": "1100"
        },
        {
            "name": "new_customers",
            "label": "New customers during the period (N)",
            "type": "number",
            "default": "250"
        }
    ],
    "outputs": [
        {
            "key": "retention_rate",
            "label": "Customer retention rate",
            "format": "percent"
        },
        {
            "key": "churn_rate",
            "label": "Churn rate",
            "format": "percent"
        },
        {
            "key": "retained",
            "label": "Customers retained",
            "format": "integer"
        },
        {
            "key": "lost",
            "label": "Customers lost",
            "format": "integer"
        },
        {
            "key": "growth_pct",
            "label": "Net customer growth",
            "format": "percent"
        }
    ],
    "formula": {
        "text": "Retention rate = (E − N) ÷ S × 100;  Churn = 100 − Retention",
        "variables": {
            "S": "customers at the start of the period",
            "E": "customers at the end",
            "N": "new customers acquired during the period"
        }
    },
    "worked_example": {
        "inputs": {
            "start_customers": "1000",
            "end_customers": "1100",
            "new_customers": "250"
        },
        "steps": [
            "Retained = 1,100 − 250 = 850.",
            "Retention = 850 ÷ 1,000 = 85%.",
            "Churn = 100 − 85 = 15%, or 150 customers lost."
        ],
        "result": "The business kept 85% of its starting customers and lost 15%, even though the total grew by 10%."
    },
    "interpretation": "Compare retention only over equal periods and with the same definition of an active customer. For non-subscription shops, define “customer” as someone who bought within a set window, such as the last 12 months.",
    "assumptions": [
        "New customers acquired during the period are not counted as retained."
    ],
    "limitations": [
        "It is a single-period figure; cohort analysis shows how retention changes with customer age."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Why subtract new customers?",
            "answer": "Otherwise acquisition can mask losses. Subtracting them leaves only the customers you started with."
        },
        {
            "question": "What counts as a customer in a non-subscription shop?",
            "answer": "Choose a rule, such as purchased in the last 12 months, and apply it to both the start and end counts."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Subscription Churn Calculator",
            "url": "https://calculators.geekmidst.com/calculators/subscription-churn-calculator"
        },
        {
            "name": "Customer Referral Reward Calculator",
            "url": "https://calculators.geekmidst.com/calculators/customer-referral-reward-calculator"
        },
        {
            "name": "Percentage Calculator",
            "url": "https://calculators.geekmidst.com/calculators/percentage-calculator"
        },
        {
            "name": "Employee Retention Rate Calculator",
            "url": "https://calculators.geekmidst.com/calculators/employee-retention-rate-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}