toolbox
Home / Startups & Digital Business / Seed Stage Runway Calculator

Seed Stage Runway Calculator

The Seed Stage Runway Calculator estimates how many months a startup can continue operating before its available cash is exhausted. It combines current cash, recurring monthly operating costs, and recurring monthly cash inflows to calculate net burn and an approximate runway end date.

The estimate is designed for early-stage planning, when hiring, fundraising, and revenue timing can materially change the cash outlook. Updating the inputs each month creates a more useful decision tool than relying on a single static forecast.

Cash runway inputs

USD
USD
USD
Result
—
months at the current net burn rate
Monthly net burn—
Approximate runway days—
Estimated cash-out date—

1. Use spendable cash
Enter cash that is actually available for operations, excluding restricted funds.

2. Enter monthly cash expenses
Include payroll, contractors, software, rent, marketing, debt payments, and other recurring outflows.

3. Add recurring inflows
Enter cash collections expected each month, not booked revenue that has not yet been received.

4. Review net burn
Confirm that expenses minus inflows reflects the startup’s recent cash movement.

5. Stress-test the plan
Recalculate with hiring, revenue, or cost scenarios to see how runway changes.

Monthly net burn = Monthly cash expenses − Monthly cash inflows
Runway (months) = Available cash ÷ Monthly net burn

If inflows equal or exceed expenses, the current model does not produce a finite cash-out date. The estimate assumes the entered monthly values remain constant.

What the result means

The result approximates how long the current cash balance can fund the business at the entered monthly net burn.

One-time expenses, financing events, delayed collections, taxes, and changes in hiring or revenue can make actual runway shorter or longer.

Given: Available cash is $900,000, monthly expenses are $140,000, and monthly inflows are $35,000.

Calculation: Net burn = $140,000 − $35,000 = $105,000. Runway = $900,000 ÷ $105,000 = 8.57 months.

Result: Estimated runway is about 8.6 months, before considering changes in spending, collections, or funding.

Should accounts receivable be included as cash?

No. Use cash already available unless collection is sufficiently certain and you intentionally model it as a future inflow.

What if monthly inflows exceed expenses?

The calculator shows no current net burn. That does not guarantee permanent sustainability because expenses and collections can still fluctuate.

Should founder salaries be included?

Include every cash expense the company expects to pay, including founder compensation when it is part of the operating plan.

Why use cash expenses instead of accounting expenses?

Runway is a cash measure. Non-cash charges such as depreciation do not directly reduce the bank balance, while debt principal and capital purchases may reduce cash even when treated differently in accounting.

How often should runway be updated?

Monthly updates are common, and more frequent reviews may be useful during rapid hiring, fundraising, or sharp revenue changes.