The Seed Funding Runway Calculator estimates how many months a startup can operate using a seed round after setting aside a reserve. It combines the deployable portion of funding with recurring operating costs and expected customer cash receipts to calculate monthly net burn and runway. This gives founders a direct way to test whether a proposed round size supports the hiring, product, and go-to-market plan.
The result is a planning estimate, not a full treasury forecast. Early-stage companies often experience uneven hiring dates, annual software payments, delayed collections, and launch-related expenses. Those events can shorten actual runway even when the average monthly assumptions appear reasonable. Use the calculator to screen funding and cost scenarios, then build a monthly cash schedule for the selected plan.
Use cash expected to be available after closing costs.
Keep contingency or restricted cash out of routine spending.
Include payroll, vendors, rent, and other cash expenses.
Use expected receipts rather than invoiced revenue.
Compare months of runway with the milestones the round must fund.
Where:
Assumptions: Costs and revenue are stable each month, and all deployable funding is available immediately. Taxes, financing fees, and irregular capital spending should be included separately when material.
The main result is an estimate based on the values entered and should be interpreted together with the supporting metrics shown.
Use consistent periods and units, and replace planning assumptions with observed data when available.
Given:
Calculation:
Deployable funding = $1,500,000 − $150,000 = $1,350,000. Net burn = $180,000 − $60,000 = $120,000. Runway = $1,350,000 ÷ $120,000 = 11.25 months.
Result: Estimated runway is 11.3 months.
The plan has slightly more than eleven months to reach milestones or secure additional capital.
A reserve prevents contingency funds from being treated as normal operating capacity. It also makes scenarios easier to compare.
Use collected or reliably collectible cash for runway planning. Accounting revenue may arrive later than the expense obligations it is meant to fund.
The calculator reports no burn-limited runway. The business may still need working capital for irregular payments and growth investments.
No. It estimates operating runway only. Equity ownership and financing terms require separate calculations.
The tool does not prescribe a target. The appropriate period depends on milestones, fundraising conditions, hiring commitments, and the company’s risk tolerance.