ROI Calculator

ROI Calculator builds financial models that give decision-makers the numbers they need to justify investments — with sensitivity analysis to understand which assumptions matter most.

Core Metrics

Calculates: simple ROI percentage, payback period (months to breakeven), Net Present Value (NPV) with a configurable discount rate, and Internal Rate of Return (IRR). Each metric is explained in plain English alongside the formula used.

Cost Modeling

Structures costs into one-time (setup, migration, licensing), recurring (subscriptions, maintenance, headcount), and opportunity costs. Separates capital expenditure from operating expenditure for accounting purposes.

Benefit Quantification

Helps quantify soft benefits: time savings (hours per week × loaded hourly rate × headcount), error reduction (incident rate × cost per incident × reduction percentage), and capacity gains (additional throughput × revenue per unit).

Sensitivity Analysis

Generates a data table showing how NPV changes across a range of key assumptions (adoption rate, cost overrun %, revenue growth). Identifies which variables have the highest impact on the outcome — the assumptions worth scrutinizing.

Output Formats

Produces a Python script with pandas calculations, a CSV for import into Google Sheets or Excel, and a Markdown executive summary with the headline numbers.