SaaS and business model feasibility calculator

1. Define the project, baseline, viewpoint and horizon. Use incremental cash changes versus that baseline—not all accounting income or sunk costs.
2. Collect the source records listed below. Date your assumptions and distinguish measured figures, signed terms, quotes and forecasts. If an essential input is unknown, investigate it rather than silently entering zero.
3. Enter base assumptions and your own downside/upside changes. Use a coherent USD price basis: nominal flows with nominal discount rates, or real flows with real rates. Do not mix them.
4. Calculate. Review the period table, zero/undefined metrics, cash deficits, scenario graph and model-specific notes. A positive NPV does not satisfy operational, legal, safety, market or financing requirements.
5. Print/save the result or download the cash-flow CSV. Result JSON preserves inputs and results; CSV carries the period table. For an equal-period model, use the optional Decision Feasibility handoff only after reviewing the numbers.

Project cash flow is before financing: exclude loan proceeds, principal and interest. Equity cash flow is after financing: equity contribution at time zero, then cash after debt service and final payoff. Do not discount one viewpoint with a rate intended for the other. Different discount rates can change the comparison.

NPV discounts all modeled net cash flows. Conventional IRR/XIRR is reported only for an initial outflow followed by nonnegative net inflows and a root in the stated range. Multiple sign changes can create ambiguous IRRs; the tool does not label one root as the answer. MIRR uses the specified finance/reinvestment rates. Payback is the first period-end recovery—not an interpolation or proof that cash stays positive afterward.

Scenario changes combine within a scenario; separate scenarios are alternatives, not cumulative events or probabilities. Longer lives and terminal values are assumptions that often dominate results. Check the source evidence before relying on them.

The explicit handoff button places the base unlevered equal-period cash flows into a temporary handoff on this device and opens the complete study. On that page, choose Load the reviewed financial cash flows to replace the current unsaved study inputs. Save an existing study first if needed. There is no automatic merge.

Only initial project outlay, period benefits/costs and the matching discount rate transfer. Financing/equity returns, matrix scores, requirements, scenario probabilities and lender permissions do not. Your funding amount, requirements, ratings and additional uncertainty remain unverified and must be entered. The handoff never grants GO status. SaaS uses monthly periods and a monthly-equivalent rate; the other transferable models use years. Dated capital flows do not transfer because the complete study expects equal periods.

There is no online project save or account created by this handoff. It uses browser session storage, which can be cleared or blocked. JSON result downloads and explicit editable complete-study files are separate features.

• Use subscription/billing records for opening paying accounts and MRR. Initial MRR is opening customers × entered ARPA; acquired cohorts join at that ARPA. Use monthly customer churn, not annual churn divided by 12 unless that conversion is justified; a consistent annual-to-monthly survival conversion is 1 − (1 − annual churn)^(1/12).
• Count expected NEW paying customers, with a separate growth assumption for new acquisitions. This is not an automatic conversion forecast from site visits or leads.
• Churn removes opening customers and proportional opening MRR. Expansion/contraction apply to surviving existing MRR. New-customer revenue is excluded from NRR/GRR. If your reporting definitions differ, reconcile them before comparing.
• Use COGS-consistent gross margin. The tool derives COGS once. Enter fully loaded cash CAC per acquired customer; acquisition spend is then CAC × new customers. Exclude those costs, COGS and setup from fixed opex to avoid double counting.
• Use starting available cash BEFORE setup. It funds runway but is not revenue and does not inflate NPV. Setup is spent at time zero. Annual discount is converted to a matching effective monthly rate.
• Cash receipts are closing MRR, including a full month for new customers; all cash occurs at month ends. This is not an annual-prepayment, deferred-revenue, receivables or invoice-collection model. No future financing or terminal valuation is assumed.
• Downside can combine higher churn, lower acquisitions, lower gross margin and increased fixed opex. Upside can improve acquisitions but also increases CAC spending, so its runway need not improve.

The tool reports closing MRR/ARR run rate, existing-cohort NRR/GRR, customer retention, CAC payback, simple and horizon-bounded discounted gross-profit LTV, fixed-cost break-even customers, first operating break-even, first negative-cash month and required starting cash. ARR is a run rate, not booked annual revenue. Zero churn does not justify infinite LTV. The break-even customer count excludes acquisition spending; operating break-even does not imply cumulative cash recovery. The cohort summary reconciles surviving customers and MRR by acquisition month.