An Excel sheet with every variable we use internally for our ROI analyses — from fully-loaded employee cost through LLM API prices to escalation effort. 7 pre-calculated scenarios ready to adjust.
Here's a shortened excerpt from Sheet 2 — the main calculation for an inbox manager at a 5-person agency. The real sheet has 40+ rows; here are just the most important ones:
The live calculator on the website is good for a quick first estimate. The Excel sheet is built for the serious investment decision — with sensitivity analyses, a 5-year projection, notes fields for assumptions and sources, and automatic charts you can drop straight into presentations.
Sheet 4 has seven pre-filled scenarios. Find the one closest to your business — and copy the values as a starting point into Sheet 1. Saves 20 minutes over a blank start.
On Sheet 1: cells highlighted in yellow are input fields. Replace the values, and every other sheet updates automatically. The 5 most important variables: fully-loaded employee cost, setup investment, monthly API cost, maintenance effort, expected lifespan of the setup.
Sheet 3 shows you instantly what happens if your assumptions swing +/- 20%. If the result is still positive under pessimistic assumptions — you have a robust investment decision. If it flips: address the risks before you invest.
Bonus tab at the bottom: your assumptions and sources. Sounds formal — but it's worth its weight in gold when you show the result to your business partner 6 months later, or when reality looks different than planned. Traceability is 80% of the learning curve.
Works in Excel 2016 and up, and in Google Sheets. No email needed — direct download.
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