Startup Runway and Burn Model: 36-month headcount plan, cash-out date, break-even, scenarios

Two questions every founder gets asked: what is your monthly burn and when do you run out of cash. This model answers both from a headcount plan and a handful of revenue and cost inputs, then lets you move three dials (growth, costs, hiring delay) and read the new cash-out date.

• Inputs: opening cash and committed funding, starting MRR, monthly growth and churn, gross margin, payment terms, rent, software (with growth), marketing, G&A, employer on-costs, a minimum cash buffer, and the three scenario multipliers.
• Headcount: one row per role with department, start month, salary and count; the monthly salary grid and FTE count follow, with the scenario hiring delay applied to every start.
• Model, 36 months: MRR, revenue, cash collected on the payment terms, salaries and on-costs, fixed costs, cost of revenue, gross burn, net burn, funding, opening and closing cash, trailing three-month average burn, runway in months, buffer flag, headcount.
• Headline: cash-out month and months of runway, lowest cash and when, burn at months 1 and 12, MRR at 12 and 36, break-even month, closing cash at 36, and the funding needed to hold the buffer.

Rebuilt independently in Python from the same inputs and matched cell by cell before listing. Every default is an example value. Live formulas, no macros, no locked cells. Excel and Google Sheets.

Who it is for: founders preparing a board update or a raise, finance leads at seed to Series A companies, investors sanity-checking a runway claim.