How much does a bad hire really cost? The complete calculation

"He didn't work out." Four months after joining, the new salesperson left — or was let go. In the income statement, this episode appears nowhere. There is no "failed hire" line in the general ledger. And yet, if you do the math item by item, the bill almost always comes to between €15,000 and €50,000 for a mid-level profile. Here is the breakdown — and the table to run the calculation with your own figures, because it's your number that counts, not a statistic.

First, define "failed"

By a failed hire, we mean here: an employee who leaves the company (or is let go) within the first six months. Termination during the probationary period, early resignation, amicable separation — the cost mechanics are the same. We exclude later departures, whose causes go beyond onboarding.

An important point: in the vast majority of cases HR directors describe, an early departure is not a pure hiring mistake. It is a mismatch that set in during the first few weeks — unclear expectations, an improvised welcome, a chaotic ramp-up, ignored warning signs. In other words, a significant share of these costs is avoidable, and that is what makes the calculation interesting.

The calculation, item by item

Item 1 — The acquisition cost (the one you pay twice)

Everything the hire cost the first time… and that you will have to pay a second time to replace them:

• Job ad postings and subscriptions (job boards, LinkedIn Recruiter…)
• A recruitment firm or headhunter, where applicable: typically 15 to 25% of gross annual salary
• Internal time: screening résumés, interviews (multiply the number of interview hours by the participants' fully loaded hourly cost — it's always more than you think)

Order of magnitude: from €2,000 (simple direct hire) to €12,000+ (headhunted profile). And this item counts double in a failed hire: what was spent, plus what will have to be spent again.

Item 2 — The salary for unproductive months

An employee who leaves after four months has almost never reached full productivity. A conservative estimation convention that is easy to defend internally:

Cost = fully loaded monthly salary × number of months present × 50%

For a salary of €40k gross per year (€4,700/month fully loaded), with four months present: **€9,400** of payroll consumed for a contribution that never got up to speed. Adjust the percentage depending on the role — a salesperson who hasn't finished ramping up or a consultant who was never staffed on an assignment can be closer to 70%.

Item 3 — The vacant position (the invisible cost)

Between the departure and the replacement's arrival — count the hiring time plus the next person's notice period, easily 3 to 5 months — the work doesn't get done, or gets done badly:

• Lost revenue (glaring for a salesperson with a target, or a billable consultant: every unstaffed day translates into lost daily rate)
• An overloaded team absorbing the work, with quality and morale wearing down
• Clients or projects put on hold

Order of magnitude: from €3,000 for a support role to several tens of thousands of euros for a role that directly generates revenue. This is the most variable item — and the one most often forgotten.

Item 4 — Other people's time

Onboarding took up a lot of people's time: the manager (briefings, training, check-ins), colleagues (questions, pairing), HR (paperwork, follow-up, then managing the departure). Onboarding typically consumes 8 to 15 hours of manager and HR time — go through it all again for the replacement, add the handling of the exit (meetings, paperwork, handover), and value it at the fully loaded hourly cost.

Order of magnitude: €1,500 to €4,000.

Item 5 — Collateral damage (real, but not to be overestimated)

An early departure leaves its mark: a team that starts asking questions, an employer brand that wears thin (Glassdoor reviews from early leavers are rarely kind), a client who has dealt with two contacts in six months. These costs are real but hard to quantify honestly — our advice: leave them out of the calculation and mention them in a note. The total of items 1 to 4 is more than enough to make the case.

The summary table

Item	Range (~€40k profile)	Your calculation
1. Acquisition ×2	€4,000 – €24,000	___
2. Unproductive salary	€6,000 – €13,000	___
3. Vacant position	€3,000 – €15,000+	___
4. Internal time	€1,500 – €4,000	___
Total	≈ €15,000 – €50,000	___

For a 150-person company with 15% turnover and even just one or two early departures a year, we're talking about several tens of thousands of euros a year — an amount that, if it appeared on a single invoice, would immediately trigger an action plan.

The avoidable part: the first few weeks

You can't bring this cost down to zero: there will always be genuine hiring mistakes. But the window where everything is decided is narrow and well identified: between the signature and the end of the third month. That is when engagement or disengagement, skill-building or getting bogged down, confidence or doubt are decided.

Three investments have an outsized effect relative to their cost:

1. Real preboarding — the new hire who receives content, human contact and their documents to sign before day 1 arrives engaged. The one who goes through two months of silence arrives wondering whether they made the right choice (why preboarding is the decisive phase).
2. A structured, measured journey — knowing who has seen what, who is progressing, who is stalling (the complete process).
3. Warning signs — a new hire who is disengaging does so silently. The signs exist (inactivity, questions that stop, missed milestones); you still have to see them in time, while a 30-minute conversation is enough to correct course.

Put together, these three investments cost a few hours of structuring and, if you use a tool, around a hundred euros a month. Against a single early departure avoided — €15,000 at the very least — the comparison speaks for itself. It's rarely a question of budget; it's a question of seeing the cost that, today, appears on no invoice.

At Weloom, we designed our AI onboarding platform around these three levers: preboarding from the signature (documents included), a journey generated from your own documents, and automatic alerts when a new hire disengages. Starting at €129 excl. VAT/month — that is, for twelve hires a year, about €130 per new hire. 14-day free trial.

To go further: see the 30-60-90 onboarding plan and audit, in twenty minutes, the window where this cost is decided.