B2B SaaS Financial Model (Series A Edition) - Deterministic Cohort & Runway Calculator for Founders

This downloadable spreadsheet provides a factory-grade financial engine for B2B SaaS operators. It is designed for founders, CFOs, and consultants who need an auditable, investor-ready projection model that won't break when assumptions change. Unlike standard templates filled with fragile formulas, phantom decimals, and unrealistic "Day 1" churn assumptions, this tool relies on strict, deterministic cohort logic.

The sheet is intentionally structured into three fixed tabs: Assumptions & Inputs, Executive Dashboard, and Engine_Logic. Users only interact with the clearly defined yellow input cells to define their pricing tiers, tier mix, acquisition targets, churn, and operating expenses. The hidden Engine Ledger dynamically calculates weighted ARPU, expansion MRR, net churn, and tracks actual "logo counts" (active customers) month over month.

The Executive Dashboard instantly visualizes the 12-month Net MRR trajectory and computes the exact metrics Venture Capitalists demand: Year 1 ARR run-rate, Blended Net LTV, Net LTV:CAC ratio, and Cash Runway. The model even accounts for real-world friction by applying a configurable Cash Collection Rate to your invoiced MRR.

By separating the inputs from the complex background calculations, you eliminate the risk of accidental overwrites, ensuring your financial story remains pristine. This makes the sheet incredibly reliable, mathematically sound, and ready to export as a clean PDF for your next board meeting.