FREE STARTUP FINANCE TOOL
Startup Runway Calculator
Estimate cash runway to a reserve and compare expense-cut scenarios.
CASH, BURN, AND RESERVE
Calculate your startup runway
Planning estimate only. This steady-state model assumes monthly revenue and expenses remain unchanged and excludes timing differences, taxes, debt payments, financing, and unexpected cash movements.
THE BASICS
What is a startup runway calculator?
A startup runway calculator estimates how many months your cash can support the current operating plan. It converts cash balance, expenses, revenue, and an optional safety reserve into a practical decision window.
Use the Burn Rate Calculator for a detailed burn analysis, and keep recurring revenue consistent with the MRR Calculator.
Startup runway formulas
Monthly net burn = monthly operating expenses − monthly operating revenueRunway to reserve = (cash balance − minimum reserve) ÷ monthly net burnRunway to zero = cash balance ÷ monthly net burnThe formulas only produce a finite runway when expenses exceed operating revenue. A cash-flow-positive or break-even company does not consume cash under steady-state assumptions.
Why use a minimum cash reserve?
Managing all the way to zero leaves no room for timing delays, severance, taxes, vendor commitments, or an orderly wind-down. A reserve makes the primary runway estimate more operationally useful while the zero-cash result remains visible as an absolute boundary.
Choose a reserve based on obligations and risk rather than a generic percentage. If the reserve already exceeds cash, operating runway is zero even though some cash remains.
Startup runway example
A startup with $500,000 in cash, $80,000 of monthly operating expenses, $30,000 of monthly revenue, and a $100,000 reserve has $50,000 monthly net burn.
| Result | Metric | Result |
|---|---|---|
| Cash balance | $500,000.00 | |
| Gross monthly burn | $80,000.00 | |
| Monthly net burn | $50,000.00 | |
| Cash above reserve | $400,000.00 | |
| Runway to reserve | 8.00 months | |
| Runway to zero | 10.00 months | |
| Cash after 12 months | -$100,000.00 |
How founders should use runway scenarios
Do not treat one runway number as a forecast. Compare hiring plans, expense reductions, collections, pricing, and fundraising timelines. The calculator’s expense-cut scenarios hold revenue constant so you can see how cost action alone changes the reserve date.
Pair runway with the planned Break Even Calculator and the SaaS Pricing Calculator. Revisit the model when cash or monthly operations move materially.
COMMON QUESTIONS
Startup runway questions
What is startup runway?
Startup runway is the estimated time a company can continue operating before its available cash reaches a defined limit, assuming the current net burn remains unchanged.
What is the difference between gross burn and net burn?
Gross burn is monthly operating cash expense. Net burn subtracts monthly operating revenue from those expenses. Runway is normally calculated with net burn.
Should runway end at zero cash?
Zero cash is the absolute limit, but founders often manage to a reserve instead. A reserve creates time for payroll, wind-down obligations, fundraising delays, or unexpected costs. This calculator shows both limits.
What if monthly revenue is greater than expenses?
The company is cash-flow positive under the entered assumptions, so a steady-state burn formula has no finite runway. Cash can still decline because of debt, taxes, financing costs, or one-time expenses not included here.
How often should I update runway?
Update it at least monthly and whenever hiring, pricing, collections, financing, or major expenses change. Use recent cash data and normalize unusually volatile months.
Does more than 12 months of runway mean the company is safe?
Not automatically. Runway is only as reliable as the assumptions behind revenue, expenses, collections, and planned commitments. Track a base case and downside scenarios.