The Founder Runway Calculator estimates how many months a startup can operate before its available cash is exhausted. It uses current cash, expected one-time cash additions, and monthly net burn, with net burn calculated from monthly cash operating expenses minus monthly cash revenue.
This view helps founders time fundraising, hiring, and cost-control decisions. It is a straight-line estimate: it assumes the entered monthly revenue and expenses remain constant and does not model changing collections, debt payments, taxes, working capital, or step changes in payroll.
1. Enter current cash
Use unrestricted cash available to fund operations.
2. Add expected one-time cash
Include committed cash inflows only when you want them included in the runway base.
3. Enter monthly cash expenses
Use actual cash operating outflows rather than noncash accounting expense.
4. Enter monthly cash revenue
Use expected cash collections for the same monthly period.
5. Review runway and net burn
The result shows months of runway and the detail row shows the monthly cash shortfall.
Monthly net burn = Monthly cash operating expenses − Monthly cash revenue. Runway in months = (Current cash + One-time cash additions) ÷ Monthly net burn.
The result estimates the number of months the available cash can support the current net cash outflow.
If monthly revenue equals or exceeds monthly operating expenses, runway is not finite under this constant-input model.
Given: $900,000 current cash, $100,000 expected cash addition, $180,000 monthly expenses, and $95,000 monthly cash revenue.
Calculation: Net burn = $180,000 − $95,000 = $85,000. Available cash = $1,000,000. Runway = $1,000,000 ÷ $85,000 = 11.76 months.
Result: Estimated runway is 11.76 months.
Only include receivables when they are entered as expected cash additions and collection is sufficiently reliable. Runway should primarily be based on actual liquidity.
Include recurring cash operating outflows such as payroll, rent, software, contractors, and cash interest. Exclude depreciation and other noncash charges.
When monthly cash revenue is at least as high as monthly operating expenses, the simple model has no ongoing net burn.
Update it whenever cash, hiring plans, revenue collections, or major commitments change. Many startups review it monthly or more frequently during fundraising.
It is one input. Fundraising lead time, milestones, market conditions, and contingency reserves should also influence timing.