Vehicles / Everyday tools

MPG fill-up tracker

Keep a local fill-up log and measure fuel economy from complete tank-to-tank intervals.

Your fill-up log.

This browser only. History is stored on this device, not uploaded. Export a backup before clearing browser data.

Recorded fills

The working, clearly explained

Behind the numbers.

FIGGYR / FIELD NOTES

How it works

The first full fill establishes a baseline; its fuel is not used in an efficiency calculation. Partial fills accumulate until the next full fill. Entries before the first full fill cannot establish an interval. Odometer readings must increase and dates must be chronological. Use a consistent full-tank method. Missing fills, odometer resets or switching vehicles invalidate comparisons.

The formulaDistance = current full-fill odometer − previous full-fill odometer
Interval fuel = all fuel added after the previous full fill, including partial fills and the current full fill
Overall economy = total completed distance / total completed fuel

Put it into practice

EXAMPLE

A full baseline at 10,000 miles, a 5-US-gallon partial fill at 10,100, and a 7-US-gallon full fill at 10,300 produce 300 / 12 = 25 US MPG.

Good to know

Where does my history go?

It is saved only in this browser’s local storage on this device. Other people using this browser profile may see it. Clearing site data removes it; private browsing or storage restrictions may prevent persistence. Export a backup to keep it.

Can I mix fuel units?

Yes. Each entry is converted to kilometers and liters internally. Results distinguish US MPG, Imperial MPG and liters per 100 km.

What happens when I delete a fill?

Intervals are recalculated from the remaining entries. Removing a fuel purchase can make the result inaccurate; export a backup before editing history.