Stop Measuring a Bad Hire by Their Salary Alone

Ask most engineering leaders what a bad hire costs, and they will quote a number close to the salary. Maybe a bit more to cover recruitment fees. It feels like a reasonable estimate. It is also consistently too low.

A long-standing benchmark often attributed to the U.S. Department of Labor puts the minimum cost of a bad hire at 30 percent of first-year earnings. The Society for Human Resource Management runs its own research too. SHRM’s Human Capital Benchmarking work puts full replacement cost at 50 to 200 percent of annual salary. That range climbs toward the top for senior technical or executive roles. Neither figure traces back to one single documented calculation. Both are industry benchmarks repeated so consistently across HR and recruitment research that they have become the standard reference point. Still useful as a floor and not a ceiling. For senior or highly specialised roles, multiple industry analyses put the realistic upper end at 2 to 5x annual salary once every cost is counted.

In Australia, recruitment industry estimates typically place the cost of a bad hire at 30 to 150 percent of salary. That range extends to 150-300 percent for senior or specialist roles. HR research is also consistent on one point. A large share of workforce turnover, often cited as near 80 percent, traces back to poor hiring decisions rather than to the employee or the role itself.

For engineering teams across Australia and New Zealand, the picture is worse than the averages suggest. This is especially true as the Australian engineering hiring market continues to tighten. Engineering roles carry a cost that a generic bad-hire statistic does not fully capture. That cost comes from getting the technical work itself wrong.

Why a Bad Engineering Hire Costs More Than a Bad Hire Anywhere Else

Most of the cost of bad-hire research is based on general workforce data. Think sales roles, admin roles, and customer service roles. Engineering is different. It pushes the number toward the higher end of the range for three reasons.

The work has to be redone by someone else. A CAD model built to the wrong tolerance, a simulation run with flawed assumptions, or a PLM structure set up incorrectly does not just sit unfinished. A senior engineer has to find the error, understand it, and rebuild it. That is paid time spent undoing work, on top of paying for it in the first place.

The delay does not stay contained to one role. Engineering sits on the critical path of product development, manufacturing and infrastructure delivery. When one seat underperforms, the milestones behind it move too. There is rarely a spare hand available to absorb the gap. Infrastructure Australia’s 2025 Market Capacity Report projects that the national shortfall of engineers, architects and scientists will peak near 126k roles in late 2026. In a market that tight, a mis-hire cannot simply be fixed with a fast replacement, as it might have been a few years ago.

The risk profile is higher. Depending on the discipline, a mis-hire can introduce compliance, quality, or safety exposure that a generic office role simply does not carry. That risk does not show up on a P&L line, but it shows up eventually.

The Seven Cost Layers of a Bad Technical Hire

The salary is just the first layer. Here is what stacks on top of it in a typical engineering mis-hire.

• Recruitment cost paid twice. Advertising agency fees and internal hours spent sourcing the original hire, then spent again to replace them.
• Salary and superannuation paid for underperformance. Full compensation for output that does not match it.
• Onboarding and training investment lost. The hours a manager and team invested to bring them up to speed walk out the door with them.
• Rework and remediation. A senior engineer’s time to identify and fix technical errors already built into designs, models, or systems.
• Project delay and opportunity cost. Milestones pushed, delivery penalties, and revenue that arrives later than planned.
• Team drags. Overtime to cover gaps, morale erosion, and the disproportionate amount of management time spent coaching, documenting, and managing out one person.
• Exit and reputational cost. Separation processes and in-delivery critical roles, potential damage to client relationships or contract standing.

Individually, several of these are easy to write off as just part of the job. Stacked together over a six- to twelve-month tenure in a senior or specialist engineering role, they are what can turn a $150k salary into more than $400k of real cost.

A Simple Formula to Estimate Your Own Risk

You do not need a finance degree to get a realistic estimate. A useful working formula for a technical role is this.

Total cost = Recruitment cost x 2 + Salary and super paid during tenure + Rework hours x senior engineer rate + Estimated project delay cost

The figures below are illustrative. They are built on stated, checkable assumptions rather than on a single real case. Substitute your own recruitment fees, salary and delay costs to estimate your actual exposure. Here is what it looks like for a mid-level design engineer on a $120k base salary who lasts eight months before the mismatch becomes unmanageable.

• Salary and super. $120k base plus Australia’s current 12 percent Superannuation Guarantee, effective 1 July 2025, equals a total package of $134.4k.
• Recruitment cost paid twice. Using a 15 percent agency placement fee within the commonly cited 10 to 20 percent range for specialist technical searches, that is $18k per round times two equals $36k.
• Salary and super paid over 8 months. $134.4k times eight over twelve equals $89.6k.
• Rework. A senior engineer spending roughly 6 hours a week for 4 months, about 17 weeks, fixing and rechecking work at $110 an hour, equals about $11.2k.
• Project delay. A single milestone slipping by three weeks on a project with an assumed $ 15k-per-week delay cost equals $45k.

Estimated total is about $182k. That is roughly 1.5 times the base salary before team morale, client impact, or the cost of the next recruitment cycle are even factored in.

Push that same scenario into a senior or specialist role. Salaries are higher, rework is more technically complex, and the seat sits closer to client delivery. The multiplier climbs toward the 2 to 5x range cited earlier. Run the numbers on your next hire before you fill the role, not after. Adjust every assumption above to match your own agency fees, delay costs, and salary bands.

Why This Keeps Happening

If the cost is this well documented, why does it keep happening? Almost always for the same reason. The hiring process rewards how well someone presents in an interview rather than how they will actually perform in the role. A CV lists the right software and the right job titles. The interview goes smoothly. Months in the gaps between sounding capable and actually delivering start to show. Usually right as they become expensive to fix.

In a tightening Australian and New Zealand engineering market, the pressure to fill a seat quickly makes this worse, not better. Roles sit open for months, shortlists shrink, and the temptation to say yes to the best candidate available rather than the right one grows with every week the role stays vacant. It is the same pressure that drives businesses toward unicorn job ads stacked with unrealistic must haves. That narrows the pool further and pushes rushed decisions at exactly the point they are most costly. For a closer look at what is driving this shift in the market, see our guide to recruiting engineering talent in Australia.

Reducing the Risk Before Day One

None of this means hiring should be treated as a gamble you simply hope pays off. It means technical capability needs to be verified before an offer goes out and not discovered afterward. That starts with clearly separating genuine must-haves from trainable gaps. It is further strengthened by structured, discipline-specific assessment rather than a standard interview alone.

This is where an engineering-first recruitment partner earns its place. Invenio’s technical recruitment team works alongside our own engineering and workforce specialists. Because we design products and run CAD and simulation tools ourselves, we understand which capabilities a role genuinely requires and how to pressure test them before you commit. It is a different starting point from that of a generalist recruiter. It is built specifically to bring the kind of risk outlined in this article down before it ever reaches your project. If you would like to see how a hiring partnership actually performs against these numbers over time, our guide to measuring recruitment ROI with a KPI framework is a useful next read.

Talk to an Engineering Recruitment Specialist

If you have a technical role open right now or one you are about to fill, it is worth having the role’s requirements pressure-tested before the shortlist is even built. Contact Invenio’s recruitment team to talk through your hiring plans, timelines, and the specific risks attached to your next technical hire.