What one resignation costs: the invoices, and the work, time and money that never get a line item. Use your own numbers. This page does not save or send anything you type.
after the pay and benefits you did not spend while the seat was empty
Fill in what you know. Everything else uses an assumption you can see and change below.
Every line, with the arithmetic behind it. Lines at $0 are not shown.
Not paying the seat is a real saving, and it is subtracted above. Work is valued at what it costs you: salary plus benefits, for both the work nobody is doing and the time colleagues spend covering it, unless you enter a different figure for what the work is worth. That keeps both sides consistent, because the pay and benefits not spent are subtracted at the same rate. A longer vacancy therefore costs more, not less.
Not counted: lost revenue or customer impact beyond the salary, and the next person who leaves because of the extra load.
The percentages for coverage, lost productivity and ramp-up are commonly used planning assumptions, not measurements of your business.