The question that ends startups: which month does the bank account hit zero? Enter your cash, your costs and your revenue growth, and it projects 36 months forward, finds your break-even month, calculates your burn multiple, and shows what three growth scenarios do to the date you run out.
Net burn is costs minus gross-profit revenue, so it falls as you grow rather than staying flat. Gross runway is cash ÷ current net burn and ignores growth entirely — it is the pessimistic number investors quote back at you. Break-even month is the first month where gross-profit revenue covers all listed costs. Burn multiple is net burn divided by net new ARR in the same month; under 1.5 is excellent, over 3 means you are paying too much for each pound of new revenue. Scenarios shift growth by −3pp/+3pp and costs by +15%/−10%, which is roughly the range real quarters land in. None of this is financial advice — it is arithmetic with your numbers.