A tint shop quoting a customer 'how soon can you get to my car?' needs to know how many crew-days its current backlog represents. Divide cars waiting by cars one crew finishes in a day, and round up — a backlog of 34 cars at 6 cars a day is not quite 6 days, but it is not 5 days either, so it rounds up to 6.
34 cars waiting at 6 cars per crew per day needs 6 crew-days to clear.
The example
Three shops with different backlog sizes and daily throughput.
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Shop | Backlog (cars) | Cars/crew/day | Crew-days needed |
| 2 | Main St | 34 | 6 | 6 |
| 3 | Airport location | 52 | 8 | 7 |
| 4 | Mobile unit | 19 | 5 | 4 |
The formula
One division, rounded up:
How it works
Straightforward, with the rounding doing the real work:
B2/C2divides the backlog by daily throughput — 34 cars at 6 a day is 5.67 crew-days.ROUNDUP(...,0)rounds up to 6, because 5.67 days means the backlog is not actually clear until partway through the sixth day — reporting 5 or even 6 rounded-to-nearest would understate the wait.
Multiply crew-days needed by a second or third crew's inverse share to see how adding staff would compress the backlog, before committing to overtime.
Try it: interactive demo
Enter the current backlog and cars finished per crew per day.
Variations
Two crews working the backlog together
Divide by combined daily throughput across all active crews to see calendar days instead of crew-days.
Different throughput for full-car vs partial (two-front-windows) jobs
Weight the backlog by job size before dividing, since a partial-tint job takes a fraction of a full car's crew time.
Pitfalls & errors
Cars-per-crew-day should reflect a realistic average, not a best-case day — film waste, a botched install needing redo, and vehicle-to-vehicle setup time all pull the real number below a shop's fastest recorded day.
Show the customer a calendar date, not a crew-day count — add crew-days needed to today's date (skipping days the shop is closed) so the answer to 'when can you get to my car' is a date, not a number they have to translate themselves.
If cars-per-crew-day is ever 0 (data entry gap for a new location with no throughput history yet), the formula returns #DIV/0!. Default to a conservative estimate until real numbers accumulate.
Practice workbook
Frequently asked questions
Should reshoots or warranty redos count in the backlog?
Is 'cars per crew per day' the same for every film type?
Stop fighting formulas. Learn them in a day.
This recipe is one of hundreds of real-world formulas we teach. Our Excel Formulas & Functions class covers lookups, logic, text, and dynamic arrays hands-on — live in Dallas–Fort Worth, Houston, Austin, Oklahoma City, Denver, or online.
See the Formulas & Functions Class