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How to Calculate Attrition Rate (And What It Tells You)

Attrition rate sounds fancy, but it’s just a way of asking:

How many people are leaving your company (or group) over time?

Whether you’re in HR, customer success, or education, attrition rate is a key metric that shows how well you’re retaining people — employees, customers, students, and more.

🙋 What is Attrition Rate?

Attrition Rate (also called churn rate in some industries) measures the percentage of people who leave a group during a specific period.

You can calculate it monthly, quarterly, or annually — depending on what you want to track.

🧮 Attrition Rate Formula

Here’s the simple formula:

Attrition Rate = (Number of Leavers / Average Number of People) × 100

Where:

  • Leavers = How many people left during the period
  • Average Number of People = (Start + End) ÷ 2

✅ Example

Let’s say:

  • You started the year with 100 employees
  • Ended with 90
  • 15 people left during the year

👉 Average employees = (100 + 90) ÷ 2 = 95
👉 Attrition rate = (15 / 95) × 100 = 15.79%

So your annual attrition rate is 15.79%.

⚙️ Attrition Rate Calculator

Attrition Rate: —

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📘 Why Does Attrition Rate Matter?

  • In HR, it helps you monitor employee turnover
  • In customer service, it shows you how many clients you're losing
  • In education, it tells you if students are dropping out
  • In subscriptions, it reflects churn and growth balance

Tracking attrition helps you improve retention, spot red flags, and make better decisions.