Cash Burn & Runway Calculator

How the cash burn & runway calculator works

Gross burn is the entered monthly cash outflow. Net burn = monthly payments − monthly receipts; a negative value is a cash surplus. Monthly cash change uses the opposite sign so its meaning is explicit.

For positive net burn, runway months = available cash ÷ net monthly burn. Zero available cash gives zero months. When burn is zero or negative, no finite depletion ratio is shown; this does not mean the business is permanently funded.

This assumes the same average flows repeat and excludes new finance, restricted funds, changing collections, exceptional payments and minimum cash reserves unless incorporated in the inputs. It is not a dated forecast: an average monthly surplus can still hide an earlier payment shortfall.

Worked example

Available cash of 100,000 with monthly receipts of 20,000 and payments of 35,000 gives 15,000 net burn and approximately 6.667 months of runway. Increasing available cash to 150,000 gives 10 months at the same burn rate.

Sources and assumptions

The source material explains the underlying calculation or pricing structure. Entered prices, costs, schedules and scenario choices are your assumptions; this tool does not obtain supplier quotes or predict actual results.

• CFI: Gross burn, net burn and runway