How to Calculate Employee Turnover Rate (Formula + Example)

Employee turnover rate is one of the most-watched numbers in any HR dashboard, and for good reason: it tells you, in a single percentage, how many people are leaving your organization. Whether you are a manager, a founder, or just curious about your own team, the calculation is straightforward once you know which numbers to use.

Why it matters

Every departure carries a cost — recruiting, onboarding, lost knowledge, and the dip in productivity while a role sits empty. Tracking turnover over time turns those scattered costs into a trend you can act on. A rising rate is an early warning; a steady or falling one is a sign that pay, management, and culture are working.

The formula, in plain words

Turnover compares the number of people who left to the typical size of your team during the same window. It takes three steps:

• Average headcount = (employees at the start + employees at the end) ÷ 2
• Turnover rate = (employees who left ÷ average headcount) × 100
• Retention rate = ((start headcount − leavers) ÷ start headcount) × 100

Using the average headcount, rather than a single snapshot, keeps the rate fair when your team is growing or shrinking during the period.

A step-by-step example

Picture a team that started the year with 120 people, ended with 130, and saw 14 people leave along the way.

1. Average headcount: (120 + 130) ÷ 2 = 125.
2. Turnover rate: 14 ÷ 125 = 0.112, then × 100 = 11.2%.
3. Retention rate: (120 − 14) ÷ 120 = 0.883, then × 100 = 88.3%.
4. If those 14 departures happened in a single quarter, annualize by multiplying the quarterly rate by 4 to estimate the yearly pace.

So this team has an 11.2% turnover rate and an 88.3% retention rate — a healthy result for many office environments, though context matters.

Common mistakes to avoid

• Using only the starting headcount as the denominator.For turnover, divide by the average; a growing team otherwise looks more stable than it is.
• Mixing up turnover and retention. They are related but use different denominators, so they will not always sum neatly to 100%.
• Comparing across very different industries. A 15% rate is high for some sectors and low for retail or hospitality. Benchmark against your own field.
• Lumping all departures together. Separating voluntary resignations from layoffs and retirements tells you far more about what you can change.

Try it yourself

Once you have your start count, end count, and number of leavers, the employee turnover calculator does the rest — including the average headcount, retention rate, and an annualized figure for short periods.