Fuel Log Template: What to Record at Every Fill-Up
June 11, 2026 · 5 min read
A fuel log only earns its keep if it can answer two questions: what is my real fuel economy, and what does fuel cost me per kilometre? Most logs fail not because people stop filling them in, but because they record the wrong columns — so the questions can’t be answered even with months of data. Here is the template that works, and the one rule that makes the numbers trustworthy.
The template: six columns
| Column | Example | Why it matters |
|---|---|---|
| Date | 2026-06-11 | Orders the log; lets you see seasonal swings. |
| Odometer | 84,612 km | The backbone — distance between fills comes from here. |
| Litres (or gallons) | 42.3 L | Fuel volume for the economy calculation. |
| Total price | €71.50 | Cost side of cost-per-km. |
| Full tank? | yes / no | The accuracy switch — see the full-tank rule below. |
| Notes | “motorway trip” | Optional, but explains outliers months later. |
Price per litre, distance since last fill, and fuel economy are all derived columns — compute them, don’t record them. Every manually-entered derived value is a chance to introduce an arithmetic error that poisons the averages.
The full-tank rule
Fuel economy can only be measured between two full tanks. Fill to the pump’s first click, drive, fill to the click again — now the litres of the second fill equal the fuel you actually burned over those exact kilometres. If a fill is partial, you simply can’t know how much fuel the distance consumed, so partial fills must be recorded (they cost money!) but excluded from economy calculations until the next full tank closes the window.
This is the single most common fuel-log mistake: treating every fill as a measuring point. The result is fuel-economy numbers that swing wildly and mean nothing.
Paper, spreadsheet, or app?
- Paper logbook — survives a dead phone battery, but computes nothing and can’t be backed up.
- Spreadsheet — flexible and free; you own the formulas. The catch is friction: nobody opens a laptop at the pump, so entries get reconstructed from receipts on Sunday, and gaps creep in.
- App — lowest friction (you log at the pump in a few taps) and the derived numbers are computed for you. The trade-off is trusting someone else’s software with your data — pick one that lets you delete or export it.
Whichever you pick, consistency beats sophistication. A complete paper log beats a spreadsheet with holes in it.
Starting today
Record today’s odometer reading and make your next fill-up a full tank — that’s your baseline; real numbers start with the second full tank. If you’d rather skip the spreadsheet, Vroom’s free plan is this exact template with the arithmetic built in: it has a full-tank toggle, computes fill-to-fill economy correctly, and works in litres or gallons. For the method behind the numbers, see how to track fuel economy accurately.