SaaS Scenario & What-If Calculator
Answer the question founders ask most: if I change one thing, what happens to my runway? Set your base case, pull a what-if lever, and compare runway, MRR and cash against the plan.
Base case
What-if levers
Change one thing (or several) and see how runway and cash move against the base case.
Price changes apply to starting MRR and assume no churn reaction, treat a big price move as optimistic.
| Metric | Base | What-if | Change |
|---|---|---|---|
| Runway | - | - | - |
| MRR at month 12 | - | - | - |
| Net burn / mo (now) | - | - | - |
| Cash at month 12 | - | - | - |
How the scenario model works
The calculator runs a month-by-month simulation for two cases, your base case and the what-if, and compares them. Each month it grows MRR by your net monthly rate (growth minus churn), takes gross margin off as cash revenue, subtracts operating costs and fully-loaded headcount cost, and draws the difference from cash. Runway is the month your cash hits zero; if revenue overtakes costs first, the case is cash-flow positive and runway is effectively unlimited.
What-if levers
- Hire / cut headcount, the biggest, fastest lever on burn. Each head adds its fully-loaded monthly cost straight to the burn.
- Growth and churn (points), small, compounding changes. Shaving a point off monthly churn or adding a point of growth moves the 12-month picture more than it looks.
- Price (ARPA), scales starting MRR. It assumes no churn reaction, so treat an aggressive price increase as an optimistic upper bound.
Why founders run scenarios
Almost every hard early-stage decision reduces to one question: if I change this, how much runway do I gain or lose? Hiring two engineers, doubling down on paid acquisition, raising prices, or cutting costs to reach default-alive, each is a scenario. Modelling it before you commit is the difference between a deliberate bet and a surprise. This tool covers a single what-if; when you need to compare several at once, goal-seek to a target, or tie it to a full three-statement model, do it in a proper financial model. It's a fast estimate, not a forecast guarantee.
Worked example: hiring two more people
A company with $600,000 in the bank and $50,000 MRR adds two hires at $11,000 a month each and loses 2.8 months of runway.
| Item | Base case | What-if: +2 hires |
|---|---|---|
| Cash in the bank | $600,000 | $600,000 |
| Current MRR | $50,000 | $50,000 |
| Monthly MRR growth / revenue churn | 8% / 2% | 8% / 2% |
| Gross margin | 80% | 80% |
| Monthly operating costs excl. payroll | $30,000 | $30,000 |
| Headcount (fully loaded $11,000 per head per month) | 8 | 10 |
| Net burn, month 1 | $75,600 | $97,600 |
| MRR at month 12 | $100,610 | $100,610 |
| Cash at month 12 (negative = shortfall) | -$100,714 | -$364,714 |
| Runway | 9.5 months | 6.7 months |
| Runway change | -2.8 months |
Frequently asked questions
What is a what-if scenario for a SaaS startup?
How does hiring affect runway?
Which scenarios should a SaaS founder model?
What is the difference between scenario analysis and sensitivity analysis?
How does a price increase change runway in this model?
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Cite this page
Citation
Adlega. "SaaS Scenario & What-If Calculator (Free)." Updated October 22, 2026. https://adlega.com/blog/tools/scenario/
Link for your article
<a href="https://adlega.com/blog/tools/scenario/">SaaS Scenario & What-If Calculator (Free)</a> (Adlega, updated October 22, 2026)
Run every scenario in one model
Adlega turns this one what-if into a live model, compare unlimited scenarios, goal-seek to a target runway, and see the full P&L and cash flow behind each.