How to calculate First-Year Turnover Rate

Formula

First-year turnover = hires who left within 12 months ÷ hires in the cohort

SQL query

This example assumes: employees(id, start_date date, end_date date). It is written in PostgreSQL syntax; date functions differ slightly in MySQL, BigQuery and SQLite, and your column names will differ from these.

SELECT DATE_TRUNC('year', start_date)::date AS hire_year,
       COUNT(*) AS hires,
       COUNT(*) FILTER (WHERE end_date IS NOT NULL AND end_date < start_date + INTERVAL '12 months') AS left_in_first_year,
       COUNT(*) FILTER (WHERE end_date IS NOT NULL AND end_date < start_date + INTERVAL '12 months')::numeric
         / NULLIF(COUNT(*), 0) AS first_year_turnover
FROM employees
WHERE start_date < CURRENT_DATE - INTERVAL '12 months'
GROUP BY 1
ORDER BY 1;

Common mistakes that make First-Year Turnover Rate wrong

• Hires from the last 12 months have not had a full year yet and must be excluded or shown separately.
• Fixed-term contracts ending as planned are not turnover; exclude them.
• Voluntary and involuntary exits tell different stories; split them if your data allows.

Ask for First-Year Turnover Rate in plain English

Instead of writing the query yourself, you can type the question. SchemaChat turns it into SQL against your connected database or uploaded file, runs it, and shows the SQL and the figures it used so you can check the answer before you share it. It does not replace your judgement about the definition: check that the query matches the formula your business uses.

• What share of each year's hires left within their first 12 months?
• Which departments lose the most new hires?