Customer churn rate: formula and example.

WITH months AS (
  SELECT generate_series(date_trunc('month', current_date) - interval '12 months',
                         date_trunc('month', current_date) - interval '1 month', interval '1 month') AS month
),
counts AS (
  SELECT m.month,
         COUNT(DISTINCT s.customer_id) FILTER (WHERE s.started_at < m.month
           AND (s.ended_at IS NULL OR s.ended_at >= m.month)) AS start_customers,
         COUNT(DISTINCT s.customer_id) FILTER (WHERE s.started_at < m.month
           AND s.ended_at >= m.month AND s.ended_at < m.month + interval '1 month') AS churned
  FROM months m CROSS JOIN subscriptions s
  GROUP BY m.month
)
SELECT month, start_customers, churned,
       ROUND(100.0 * churned / NULLIF(start_customers, 0), 1) AS churn_pct
FROM counts
ORDER BY month;

Customer Churn % =
VAR StartDate = MIN('Date'[Date])
VAR StartCustomers =
    CALCULATE(
        DISTINCTCOUNT(Subscriptions[customer_id]),
        Subscriptions[started_at] < StartDate,
        ISBLANK(Subscriptions[ended_at]) || Subscriptions[ended_at] >= StartDate,
        REMOVEFILTERS('Date')
    )
VAR Churned = CALCULATE(DISTINCTCOUNT(MrrMovements[customer_id]), MrrMovements[movement_type] = "churn")
RETURN
    DIVIDE(Churned, StartCustomers)