Car Maintenance Schedule Calculator
Enter today's date, the odometer reading and how far you drive in a year, then for each item the last service and its interval. The intervals shown are typical figures to replace with the ones in your owner's manual.
Next item due
Tire rotation
Next due date
December 16, 2026
Status
Due in 76 days
Days until next item (negative = overdue)
76
Items overdue
0
Items due within 365 days (including overdue)
2
How it works
Each service item can have a mileage interval, a time interval or both. With both, the item falls due at whichever limit is reached first. An interval of 0 means that limit does not apply; an item with both set to 0 is left out.
The mileage limit is the odometer reading at the last service plus the mileage interval. The miles still to go are turned into days at your average daily distance (miles per year ÷ 365) and rounded down to a whole day, so the date shown never falls after the day the limit would be reached. A limit already passed gives a date in the past and the item shows as overdue.
The time limit counts calendar months: the interval minus the months since the last service, added to today's date. A month without a matching day uses its last day.
The table lists every item with its due odometer, due date and status, and the summary picks out the item due soonest.
Formula
next due miles = last service miles + mileage interval miles left = next due miles − current miles mileage due date = today + ⌊miles left × 365 ÷ miles per year⌋ days time due date = today + (time interval − months since service) months due date = earlier of the two (where both apply)
Example
Today is October 1, 2026, the odometer reads 45,000 and the car covers 12,000 miles a year. Tires were last rotated at 40,000 miles; with a 7,500-mile interval the next rotation is at 47,500 miles, 2,500 miles away. That is 2,500 × 365 ÷ 12,000 = 76.04 days, rounded down to 76, so it is due December 16, 2026, the soonest item.
Brake fluid changed 30 months ago on a 36-month interval is due in 6 months, April 1, 2027. Coolant last changed 45 months ago at 0 miles, on 5 years or 100,000 miles, reaches the time limit first: 15 months from now, January 1, 2028, while the mileage limit is 55,000 miles (1,672 days) away.
Assumptions and limitations
- Every interval is a figure you enter. The defaults are typical published ranges, not your vehicle's schedule: the owner's manual states which items apply, their intervals, and any severe-service schedule for towing, short trips, extreme temperatures or dusty roads. Engines with a timing chain have no timing belt to replace.
- Driving is assumed to be spread evenly over the year at the miles per year you enter, so mileage dates are estimates.
- Months since the last service are whole months counted back from today; enter the nearest whole month.
- Some schedules call for inspection rather than replacement, or adjust intervals with a maintenance monitor; neither is modelled.
- This is a planning estimate, not a substitute for the vehicle manufacturer's maintenance schedule, warranty requirements or a technician's inspection.
Frequently asked questions
What if my manual lists both miles and months for an item?
Enter both. The item falls due at whichever is reached first, and the table's "Limit reached first" column shows which one set the date.
How do I leave out an item my car does not have?
Set both its mileage interval and its time interval to 0. It stays in the table as "Not scheduled" and does not count toward the next item due.
More in Automotive calculators.