How to Calculate Employee Turnover Rate & Cost

Employee turnover is one of the most under-measured line items in any operating budget. This guide walks through how to calculate employee turnover rate, then breaks down the specific variables that make up the true cost of employee turnover — from recruiting spend to productivity loss during ramp-up.

The employee turnover rate formula

The standard formula is simple:

Separations is the number of employees who left during the period (voluntary + involuntary). Average headcount is (starting headcount + ending headcount) ÷ 2 for the same period.

Example: A company starts January with 200 employees, ends December with 220, and lost 30 people over the year. Average headcount = (200 + 220) ÷ 2 = 210. Turnover rate = 30 ÷ 210 × 100 = 14.3%.

Voluntary vs. involuntary turnover

Track them separately. Voluntary turnover (resignations) signals engagement, comp, or manager problems. Involuntary turnover (terminations, layoffs) reflects hiring quality and business conditions. Blending them hides the actual lever you can pull.

The variables that make up employee turnover cost

Once you know your rate, the next question is what each departure actually costs. SHRM and Gallup research consistently puts the fully-loaded cost of losing an employee at 50–200% of their annual salary. Here's where that number comes from:

1. Recruiting cost

Job board fees, recruiter commissions (typically 15–25% of first- year salary for agency hires), employer-brand spend, and internal recruiter time. Include the hours hiring managers and interview panels spend screening and interviewing — multiply by their fully-loaded hourly rate.

2. Onboarding & training cost

HR onboarding time, IT setup, equipment, training materials, and the hours peers and managers spend teaching the new hire. Most roles absorb 40–100 hours of colleague time in the first 90 days.

3. Productivity loss (ramp-up)

A new hire typically reaches full productivity somewhere between 3 and 12 months depending on role complexity. If a replacement is at 50% productivity for their first 6 months, that's roughly 3 months of lost output — often the single largest bucket in the total.

4. Vacancy cost

Days the seat sits empty × the daily value that role generates. For revenue-generating roles this can dwarf every other line.

5. Knowledge loss & team disruption

Institutional knowledge that walks out the door, projects that stall, customer relationships that need rebuilding, and the morale hit on remaining team members — harder to quantify, but real.

Putting it together

Total cost of a single departure = Recruiting + Onboarding + Productivity loss + Vacancy cost + Knowledge/disruption. Multiply that by your annual separations to get the yearly bill your P&L never labels.