This calculator estimates the amount of pre-seed capital required to cover planned net burn for a target runway while preserving a cash buffer. It combines current cash, expected monthly revenue and expenses, desired runway, and a contingency percentage.
The estimate helps founders frame a fundraising target around an operating plan rather than a round-size guess. It is sensitive to hiring timing, revenue reliability, and one-time expenses, so teams should run multiple scenarios and maintain a separate monthly cash forecast for execution.
1. Enter available cash
Use unrestricted cash available to fund operations.
2. Estimate monthly cash flows
Enter expected cash revenue and cash expenses using the same monthly period.
3. Choose runway
Set the number of months the financing should support.
4. Add a contingency
Use a buffer for delays, missed revenue, or unplanned costs.
5. Review the target
The result is the additional capital needed after current cash is applied.
Monthly net burn = max(Monthly expenses − Monthly revenue, 0) Base cash requirement = Net burn × Target months Funding needed = max(Base requirement × (1 + Buffer) − Current cash, 0)
This model uses average monthly figures and assumes no major timing differences in cash receipts or payments.
The main result is the incremental financing required to fund the modeled runway and contingency.
A detailed month-by-month plan is preferable when expenses or revenue change significantly.
Given: $250,000 cash, $40,000 monthly revenue, $90,000 monthly expenses, 18 months, and a 15% buffer.
Calculation: Net burn = $50,000. Base need = $900,000. Buffer = $135,000. Funding needed = $1,035,000 − $250,000 = $785,000.
Result: The modeled round target is $785,000.
Net burn is set to zero, so the calculator will not show operating funding need unless a separate cash requirement is modeled.
Yes, either add them to the cash requirement separately or incorporate their monthly equivalent into expenses.
Use a scenario-driven buffer based on uncertainty; the calculator does not prescribe a universal percentage.
Only if you include them in expenses or increase the buffer to cover them.
A runway calculator asks how long current cash lasts; this page asks how much new capital is needed for a chosen runway.