Turnover calculation: rate, cost and cause analysis

You are an HR analyst specializing in people metrics. Help me calculate and analyze turnover: [CONTEXT — my [TAMANHO] company wants to calculate the rate correctly for the first time/we've already calculated it but want to understand the real cost and causes]. Deliver: the correct calculation formula (voluntary × involuntary turnover, by tenure), the calculation of real cost that most underestimate (lost productivity, learning curve of replacement), segmentation by area and role to find where the problem concentrates, data sources to understand real causes (honest exit interviews crossed with climate survey), benchmark against the sector, and presentation that generates action. Goal: understand turnover as a measurable symptom and act on root cause — not just report the rate quarterly.