Know what your car actually costs
Log fuel fill-ups and service events. Watch your fuel economy trend. Keep every receipt's worth of data in one private place.
Add an Entry
Quick Service Presets
Full History
| Date | Type | Odometer | Details | Cost | Economy | Note | Actions |
|---|
Your log is empty. Add entries using the form above.
How to Get the Most from FuelLog
Setting Up
Type your vehicle name at the top and pick your unit system. Click Save Vehicle. That name appears on your dashboard and printed reports. You only need to do this once. The name is stored in your browser.
Logging Fuel
Every time you fill up, enter the date, odometer reading, how much fuel you added, and what you paid. The tool calculates fuel economy by comparing this fill-up to the last one. For the most accurate numbers, always fill until the pump clicks off. If you do a partial fill, mark it so you know the economy number will be off.
Logging Service
Use the Service tab for oil changes, tire rotations, brake jobs, and anything else. Pick a type from the dropdown or type your own. Add the cost and any notes. Service entries do not affect fuel economy but they do add to your total cost tracking.
Reading the Dashboard
The dashboard shows your average fuel economy across all fill-ups, total spending on fuel and service, and cost per mile or kilometer. The bar chart shows your last 10 fuel economy readings so you can spot trends. A sudden drop might mean it is time for new spark plugs or a tire pressure check.
Common Mistakes
Skipping fill-ups is the biggest one. If you miss logging a tank, the next calculation will span two tanks and show a misleading number. Entering the wrong odometer reading is another. Double-check the number before you save. Mixing units (miles on one entry, kilometers on another) will also break the math.
Backing Up Your Data
This tool saves everything in your browser. If you clear your browser data or switch computers, your log is gone. Use the Export button to download a JSON file. Store it somewhere safe. Use Import to load it back in on any device. You can also print the history table for a paper copy.
Questions People Ask
Can I use this for a motorcycle or truck?
Yes. The tool works for any vehicle. Just name it appropriately and log your fill-ups the same way.
What if I switch from miles to kilometers mid-log?
Pick one unit system and stick with it. The fuel economy calculation depends on consistent units. If you need to switch, export your data, clear the log, change the unit setting, and start fresh.
Does this work offline?
Yes. Once the page loads, everything works without an internet connection. Your data stays on your device.
Can I share my log with someone?
Export the JSON file and send it to them. They can import it into their own browser. There is no built-in sharing link, but the export file is small and easy to email.
Why is my first fill-up missing an economy number?
The tool needs two fill-ups to calculate economy. The first entry has no previous reading to compare against. The second fill-up will show the first economy calculation.