On most cars you reset the trip odometer by pressing the trip button (on the instrument cluster or the steering wheel) until the display shows Trip A or Trip B, then pressing and holding it for a couple of seconds until the number drops to zero. Only the trip meter resets. The main odometer, which counts the car’s lifetime distance, can’t be reset.
Once you can zero it at will, the trip meter becomes a useful measuring tool: fuel economy per tank, distance to a turn, range per charge on an EV, or a check on your average speed.
How do you reset a trip odometer? #
The general method works on almost every car made in the last few decades:
- Park, or at least wait until you’re stopped. Some cars only allow a reset when stationary, and it’s not something to fiddle with while moving.
- Switch the display to the trip meter. Press the trip or odometer button, or scroll with the steering-wheel buttons, until you see “Trip A”, “Trip B” or “Trip”.
- Press and hold the same button (or the OK/select button) for two to three seconds.
- Check it reads 0.0. If the total odometer is still showing, you were on the wrong screen; go back to step 2.
Where the reset button is on different dashboards #
| Dashboard type | How to reset |
|---|---|
| Small stalk or button poking out of the instrument cluster | Press to cycle ODO, Trip A, Trip B; hold on the trip you want |
| Steering-wheel buttons with a digital display | Scroll to the trip screen, then hold OK or select |
| Touchscreen with a trip computer menu | Open the vehicle or trip menu and tap reset for that trip |
| Older mechanical odometer with a reset knob | Push or turn the knob next to the gauge; don’t force it |
| Motorcycle | Use the mode or select button, often held for a few seconds or pressed with another button; do it stopped |
| Bike computer | Usually a long press on the main button on the trip screen |
If yours doesn’t respond, the owner’s manual will have a page on the trip computer. Some cars need the ignition on, and some reset only one trip at a time.
What’s the difference between Trip A and Trip B? #
They’re two independent counters. Resetting one doesn’t touch the other, so you can measure two things at once. A common setup:
- Trip A per tank or charge. Reset it at every fill-up. It tells you how far you’ve gone on the current tank.
- Trip B per journey or per service. Reset it at the start of a road trip, or at an oil change to count toward the next one.
On many cars, resetting a trip also resets the average fuel economy and average speed tied to that trip. That’s useful when you want fresh figures for a new tank, and annoying if you reset by accident.
How do you calculate MPG with the trip odometer? #
This fill-up method is the reference that dashboard fuel economy displays are measured against.
- Fill the tank until the pump clicks off. Don’t top it up past the click.
- Reset the trip meter before you drive away.
- Drive normally until you need fuel. The more of the tank you use, the more accurate the result.
- Fill up again to the first click, at the same pump if you can, and note how much fuel went in.
- Divide the trip distance by the fuel added.
For example, 342 miles on 11.4 US gallons is 30.0 mpg. In metric, divide litres by kilometres and multiply by 100: 38.5 litres over 550 km is 7.0 L/100 km.
A few things to know when comparing numbers:
- US and UK gallons differ. A UK (imperial) gallon is about 4.55 litres and a US gallon about 3.79, so UK mpg figures are about 20% higher for the same car. Multiply US mpg by 1.2 to get UK mpg.
- To convert US mpg to L/100 km, divide 235 by the mpg. 30 mpg is about 7.8 L/100 km.
- One tank is a noisy sample. Pumps click off at slightly different levels. Average three or four tanks for a figure you can trust.
- Your car’s own display can differ from the fill-up figure by a few percent. The fill-up method is the one to trust.
The trip distance itself carries your odometer’s error, which moves with tyre wear and tyre size. If you want to know how big that error is, our guide to trip odometer vs GPS distance shows how to test it.
What else can you measure with a trip odometer? #
- Distance to a turn. Directions like “turn left after 4.2 miles” are much easier to follow with the trip meter zeroed at the last junction.
- Average speed. Divide a leg’s distance by the time it took. 150 miles in 2 hours 30 minutes is an average of 60 mph.
- EV range. Reset at a full charge and you’ll learn your real range in summer and winter, which is often quite different from the rated figure.
- Towing economy. Reset for a tank with a trailer and a tank without, and you’ll see what the trailer costs you.
- Service intervals. Trip B reset at an oil change is a simple reminder for the next one.
Using a GPS trip meter as a second counter #
A phone makes a handy second trip meter, especially in a rental car with controls you haven’t learned yet, or when you want to keep a record of each leg. Speedometer GPS works like a trip computer: press Start and it counts distance, top speed, average speed and time from that moment. Reset clears it, and Save puts the trip in your history with the route drawn on a map, a speed chart and a lifetime odometer that adds up every saved trip. It works without mobile data and keeps everything on your phone.
Set it up the way you’d set a sat-nav: mount the phone, press Start, then drive. Keep the app open on screen, since it only reads your location while it’s running. On normal roads its distance tracks the car’s closely, and in very slow stop-and-go traffic it can come out a little short because it filters out small movements to avoid counting GPS drift. For how resetting and saving work across a multi-stop day, see reset vs save for multi-leg trips. If your dashboard speed and the app’s speed don’t match, why your speedometer reads higher than GPS explains it.
Frequently asked questions #
Can you reset the main odometer? #
No. The main odometer records the car’s total distance and isn’t meant to be reset. Altering it is illegal in the US and many other countries, because buyers rely on it to judge a used car. Only the trip meters are yours to reset.
Does resetting the trip odometer reset fuel economy? #
On many cars, yes. The average fuel economy and average speed shown with a trip are usually tied to it and clear when you reset it. Check your owner’s manual if you want to keep one without the other.
Why won’t my trip odometer reset? #
The most common reason is that the display is showing the total odometer rather than a trip meter. Switch to Trip A or Trip B first, then press and hold. Some cars also need the ignition on or the car stationary.
How accurate is the trip odometer for measuring distance? #
It’s usually close, within a percent or two on the correct tyres, but it moves with tyre wear, tyre size and pressure. Checking it against highway distance markers or a GPS trip on an open road will show you your car’s error.
Does disconnecting the battery reset the trip odometer? #
On many cars it clears the trip meters and trip computer data, while the main odometer stays untouched. If you’re replacing a battery mid-trip, note the trip reading first.