Every vendor's built-in ROI calculator assumes best-case adoption and quietly ignores the humans who have to review its output. This one doesn't. It models hours saved against the subscription, the one-time setup cost, and the ongoing time someone spends supervising the tool — then lets you compare a conservative, expected, and optimistic adoption scenario side by side, so the number you take into a budget meeting is one you can actually defend.
Why adoption, not just hours saved, decides the outcome
The single biggest lever in this model isn't the subscription price — it's the adoption factor. A vendor's demo shows the tool working perfectly every time; a real team hits edge cases, needs retraining, and only gradually folds a new tool into its workflow. This calculator scales the promised hours saved by 0.5 (conservative), 0.8 (expected), or 1.0 (optimistic) to reflect that gap. For any go/no-go decision, start with the conservative scenario — if the tool still pays for itself there, the case is solid.
The costs vendors leave out
Two costs rarely appear in a vendor's own ROI pitch: implementation and oversight. Implementation is the one-time cost of integration, data migration, and training — real money that has to be earned back before the tool is net-positive. Oversight is the ongoing time someone spends reviewing AI output or babysitting an automation; this calculator treats it as a flat, org-wide cost rather than multiplying it by team size, since one reviewer typically covers the whole team regardless of how many people use the tool.
Reading payback, ROI, and NPV together
The model uses 50 working weeks. Payback recovers the one-time implementation cost from net savings. ROI divides total net savings over the horizon, after implementation, by total subscription and implementation costs.