What the calculator is actually doing
The tool works from your own figures rather than an industry multiple, because published coaching ROI numbers are mostly unusable for an individual decision. They aggregate across wildly different engagements, are frequently produced by parties with an interest in the result, and rarely separate coaching's effect from everything else happening at the same time.
What can be estimated honestly is narrower: the cost of specific problems you already have, and how much of that cost would need to be avoided for the engagement to pay for itself.
The inputs that carry the most weight
Regretted attrition dominates most calculations. Replacing a senior contributor costs a substantial multiple of salary once recruitment, vacancy, and the ramp to full productivity are included, and the figure is usually larger than people expect. One retained person often covers an entire engagement.
Time recovered is the second input. If a leader spends six hours a week on work that should sit with someone else, that has a defensible hourly value, and it recurs weekly.
Decision quality is the third and the least tractable. It is occasionally the largest item by an order of magnitude — one hire not made, one contract structured differently — and it cannot be forecast, only observed afterwards.
Reading the output honestly
The number the calculator returns is a break-even threshold, not a prediction. It tells you what would have to change for the spend to be justified, which is a more useful question than what return you should expect.
If the threshold looks easily clearable — one fewer regretted departure over a year, say — the decision is straightforward. If it requires several things to go right simultaneously, that is worth knowing before committing rather than after.
What the calculation does not capture
Two things sit outside it. Effects that appear beyond the engagement, since skills that transfer keep returning value for years, and the tool deliberately does not attempt to model that. And costs avoided that you never observe — the resignation that did not happen, the conflict that did not escalate — which are real and unmeasurable by construction.
Related: what the ROI research actually shows and is executive coaching worth it.