Most reminders only count miles. A car that sits still needs its oil changed too — so this checks both limits for every service at once.
Owner’s manuals write most intervals as “every X miles or Y months, whichever comes first”. Type the intervals from your manual, when each service was last done and the odometer at the time. Your own driving turns the mileage limit into a date, and the earlier of the two dates wins.
| Service | Every (miles) | Every (months) | Last done | Odometer then | Next due | Miles left | Status |
|---|---|---|---|---|---|---|---|
Rules, the same as the spreadsheet: a service is OVERDUE once its months are up or its miles are used; Due soon within 500 miles or 30 days; an item done on January 31 with a 1-month interval is due on February 28, not March 3. The example intervals are only examples — use the numbers in your owner’s manual. The date by miles is an estimate from the monthly mileage you type.
Most manuals give two limits for a service, such as a number of miles and a number of months. The service is due when either one is reached. Someone who drives a lot hits the mileage first; someone who barely drives hits the months first.
Many manufacturers say yes, which is why their schedules include a time limit as well as a mileage limit. Check your own owner's manual - the months column on this page is there so a car that sits in the garage still gets its reminder.
From your owner's manual or the maintenance schedule for your exact vehicle. The numbers already on this page are examples only, and intervals vary a lot between makes, engines and driving conditions.
It divides the miles left by your average daily driving, taken from the monthly figure you type. The spreadsheet does the same thing with the odometer readings you actually log, so the estimate follows the way you really drive.
The calculator above is deliberately simple. The full spreadsheet does the whole job — 14 services for up to three vehicles, a fuel log with real full-tank MPG, every repair and running cost, cost per mile, and a dashboard that sorts what is due next. It opens in Excel and works just as well in free Google Sheets.
Get the full Car Maintenance & Vehicle Cost Tracker Or start with our free Mini Budget Tracker