A sold-out machine earns nothing until you drive back. Divide the units in the machine by its daily sales and round down — that is how many full days you have to get there.
84 units selling 12 a day gives 7 full days of stock — the gym machine at 90/24 gives just 3.
The example
Three machines, each with current stock and average daily sales.
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Machine | Units on hand | Units / day | Days left |
| 2 | Lobby snacks | 84 | 12 | 7 |
| 3 | Gym drinks | 90 | 24 | 3 |
| 4 | Office combo | 65 | 9 | 7 |
The formula
Round down — a partial day of stock is not a safe day:
How it works
The division is a countdown clock:
B2is the units currently in the machine, from your last service visit.C2is average units sold per day — total sales since last visit divided by days elapsed.ROUNDDOWNkeeps only full days; 3.7 days of stock means you plan for 3.
Sort the route by this column and the machines closest to empty rise to the top of the run sheet.
Try it: interactive demo
Enter the units in the machine and its average daily sales.
Variations
Restock-by date
Add the days to today for a calendar date the route can act on.
Flag urgent machines
Mark anything with under 3 days of stock.
Pitfalls & errors
Daily sales are an average — a Monday-heavy office machine can empty in half the predicted days. Pad high-variance locations.
Recompute the daily-sales figure at every service visit; a location's velocity drifts with seasons and headcount.
Practice workbook
Frequently asked questions
Why round down and not up?
How do I get units per day?
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