Hiring ROI calculator · Software engineer · CAD

The perfect-match tax

What does it cost to keep a role open for months, waiting for the 100% match? Compare that with hiring a fast learner who fits most of the brief and grows into the rest. Move the sliders to match your own role.

At a glance: how much the role matters

Cumulative net value, month by month

Fast learnerPerfect matchFast learner, then rehire

Value the role produces minus everything you spend on it: search, salary, training and expected mis-hire cost. Filled dots mark hire dates. The hollow dot marks the fast learner leaving. Below zero, the role is still costing more than it returns.

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Your assumptions

The role

Wait for the perfect match

Hire the fast learner

Cost details

Diminishing returns of screening more

Expected fit score of the best applicant, by how many applications you review.

How the math works

  • An empty seat loses the value the role would produce, set at salary × the value multiplier. You also save that salary while the seat is empty, and the model counts it.
  • After the start date, output starts at the day-one level and climbs in a straight line to 100% by the end of the ramp-up period. Salary plus benefits is paid from day one.
  • Recruiting time = applications × screening minutes + interviewed candidates × interview hours, at a blended hourly rate, spread over the search.
  • Job ads and tools are paid for every month the role stays open.
  • The fast learner gets a training budget and mentor hours during ramp-up.
  • Rehire from the shortlist: the first fast learner leaves, you pay an exit cost, run the same search again, and the replacement gets a new training budget and a full ramp-up.
  • Bridge: you keep the perfect-match search open the whole time, and the fast learner covers the seat until the perfect match starts, then leaves with an exit cost.
  • A fast learner who doesn't work out produces a reduced share of a good hire's output.
  • Mis-hire risk is priced as risk % × 30% of first-year salary, the US Department of Labor estimate.
  • Applicant hours are the time candidates spend applying. That cost lands on the market, so it stays out of the dollar totals.

Where the defaults come from

  1. Time to fill, software engineers (internal search: mid-level 6-9 weeks, senior 9-13, staff 13-20+): KORE1, 2026
  2. Value of a role at 1-3× salary, cost-of-vacancy method: Dr. John Sullivan
  3. Developer ramp-up: about 3 months for seniors, 4-6 months for mid-level in complex codebases: DEV Community onboarding metrics
  4. Bad hire at 30% of first-year earnings (US DOL): summary of DOL and SHRM figures
  5. Hiring for skills is 5× more predictive of performance than education and 2× more than work experience: McKinsey, citing Hunter & Hunter (1984)