The maths employers avoid doing

When a good person resigns, most organisations count the recruitment fee and stop there. It is the smallest line on the bill.

We would gently suggest doing the sum properly, once, for one real role. It is uncomfortable arithmetic, which is probably why so few leadership teams ever sit down and finish it.

What a resignation actually costs

Start with the visible pieces. The advertising, the agency percentage, the hours of management time spent shortlisting and interviewing while the day job waits. Then onboarding, which is never a week of inductions. Oxford Economics put the average UK cost of replacing an employee above £30,000 back in 2014, and found that most of it was not the hiring at all. It was the 28 weeks the new person takes to get up to full speed, more than half a year of salary paid for partial output while colleagues cover the gap.

Gallup's 2019 estimate is blunter. Replacing an employee costs between half and twice their annual salary, and Gallup called that conservative. On a €60,000 role, that is somewhere between €30,000 and €120,000. Closer to home, a 2018 survey by Adare HRM put the average Irish replacement cost at €13,100, and nothing about the years since suggests it has fallen.

Even those figures leave things out. Client relationships that took a decade to build and quietly drift when the familiar name leaves. Institutional knowledge nobody thought to write down. And the load that lands on whoever remains, which is where the next resignation often starts. Departures have a habit of travelling in twos and threes, and the second one is rarely a surprise to the team. Only to leadership.

The cost that never books itself

Resignation is at least a dated event with paperwork. The larger cost never announces itself at all. Deloitte's 2024 UK analysis put the cost of poor mental health to employers at £51bn a year, and the striking part is the split. Absence accounts for about £7bn. Presenteeism, people at their desks but running well below themselves, accounts for around £24bn. The people you can see cost multiples of the people you cannot.

So the true bill for looking away has three parts. The leavers you replace at half to twice a salary. The absences you cover. And the much larger group who are present, struggling and slowly deciding, which no report currently shows you. The same Deloitte analysis found that employers who invest in mental health see an average return of £4.70 for every £1 spent, which tells you the arithmetic works in both directions.

The line that is missing from the budget

None of this argues for panic. It argues for visibility. In our clinical work, the person who resigns in October was usually carrying something in April, and at that point it was still a conversation, a workload adjustment, a bit of support at the right time. What was missing was anyone having a hand on the pulse early enough to notice.

That is what a preventative programme is for. Monthly, confidential one-to-one sessions for every member of staff, delivered by qualified psychologists and accredited psychotherapists outside the management reporting line, with the same clinician each time. Individual sessions stay private. Only anonymised themes reach leadership, so you learn that pressure is building in one area months before it becomes a resignation letter, without ever learning a name.

Doing nothing is not free. It is just unbudgeted, and the invoice arrives on its own schedule, one Tuesday resignation at a time.