Oil Change Interval Calculator
Type in your odometer, the oil you use and how the car really gets driven, and this works out how far you can go between changes — then keeps a log so the next answer comes from your own history. Everything stays on this device: no account, no login, nothing sent anywhere.
Tick anything that describes how this car actually gets driven. Most owner's manuals call this the severe schedule, and most people drive on it without realizing.
Your oil change log
This is a planning aid, not mechanical advice. Manufacturer intervals vary widely between engines, and an oil life monitor on the dash knows more about your engine than any calculator does. When the manual and this page disagree, follow the manual.
Why one number does not fit every car
The 3,000-mile rule is a leftover from the era of conventional oil in engines with looser tolerances. Full synthetic in a modern engine routinely goes two or three times that far. But the opposite mistake is just as common: someone reads 10,000 miles on a forum, then drives four miles to work in winter, which is close to the hardest life an engine can have. Cold short trips never boil the moisture and fuel out of the oil, so it degrades faster than the mileage suggests.
That is why this page asks two separate questions — what oil is in there, and how the car actually gets used — and gives you a mileage figure and a month figure. Whichever runs out first is your change.
The log is the part that pays off
One calculation tells you when to change the oil next. Four logged changes tell you something more useful: how far you genuinely go between changes, as opposed to how far you meant to. The chart on this page plots the gap between each logged change, and after a few entries the pattern is usually clearer than anyone’s intention. It also becomes a service record you can print, which is worth real money when you sell the car.
Questions people ask
How often should I really change my oil?
For most modern cars on full synthetic, somewhere between 7,500 and 10,000 miles or once a year is typical, and conventional oil is usually 5,000 miles or six months. The number in your owner’s manual beats any general figure, because it is written for your specific engine.
What counts as severe driving?
Short trips where the engine never fully warms up, towing, extreme heat or cold, long idling and dusty or salted roads. Manufacturers list these as a separate severe schedule with a shorter interval. Ticking two or more boxes here shortens the suggested interval.
Does oil go bad if I barely drive?
Oil degrades with time as well as mileage, which is why the calculator gives you a month figure alongside the mileage. A car that covers 3,000 miles a year still needs its oil changed on the time schedule.
Is my data stored anywhere?
No. The inputs and the log live in your browser’s local storage on this device only. Nothing is uploaded, and clearing your browser data or using another device starts you fresh.