Ember & Oak, a full-service restaurant, holds $22,800 in cash against a monthly burn of $6,000, everything included: rent, gear, software, and the owner draw. That is 3.8 months of runway at current burn. Under the four-month line, so the watchlist stays lit.
Runway = cash on hand ÷ monthly burn, using your heaviest recent burn month rather than your cheapest. The full reasoning, including what to do at each runway level, lives in the main runway guide; the calculator runs it with your numbers in your browser.
The twist for restaurant owners
Restaurant burn is lumpy: rent and payroll are fixed but food cost rides revenue, so compute burn from your heaviest recent month. A slow January against December burn is how 3.8 months becomes 2 in practice.