What is a fleet fuel log?
A fleet fuel log is a record of every refill: which vehicle, when, how many liters, at what price, and the odometer reading at the time. Kept consistently, it is the simplest way to know what each vehicle consumes and costs, and the first place to look when the fuel bill does not match the work done.
This fleet fuel log spreadsheet turns those entries into figures you can act on. It calculates consumption in liters per 100 km between full tanks, totals each vehicle's liters and cost for the month, and marks the rows that need a second look. It works as a fuel tracking Excel file for a few vehicles or a small fleet, with no macros or add-ins.
How to use the fuel log template in Excel
- Open the Settings sheet. Enter your currency, the flag threshold (20% by default), and each vehicle with its ID and tank capacity.
- Delete the example rows on the Fuel log and Idling sheets. The formulas stay in place.
- Record every refill with date, vehicle, odometer, liters and price per liter. Choose "Yes" in Full tank only when the tank was filled to the top.
- Review the Check column weekly. Filter it to see only flagged rows and resolve them while the receipts are still easy to find.
- At month end, set the month on the Settings sheet, read the Monthly summary and run the Fuel card audit before approving the statement.
How does the template calculate L/100 km and fuel cost?
The template uses the full-to-full method, the standard way to measure consumption from refills. Consumption is calculated only for a full-tank refill that has an earlier full tank for the same vehicle.
Partial fills in between are added to the next full-tank interval, so their liters are not lost. On the Monthly summary, consumption is total interval liters ÷ total interval distance × 100 (L/100 km) for intervals that ended in the month, and fuel cost per km is that consumption ÷ 100 × the average price paid.
With the example rows, TRK-07 used 736 liters over 2,290 km between full tanks in October, or 32.1 L/100 km. At an average price of 1.12 per liter, that is a fuel cost of about 0.36 per km.
What do the flags in the Check column mean?
Each row is tested in this order, and the first check that applies is shown:
- Vehicle not in listThe vehicle ID is not on the Settings sheet. Usually a typing error or a new vehicle.
- Missing odometerNo reading was recorded, so this refill cannot be tied to a distance.
- Odometer not increasingThe reading is not higher than the previous refill of that vehicle.
- Above tank capacityMore liters than the tank holds. Check the receipt and the vehicle on the card.
- Consumption above averageL/100 km is higher than the vehicle's own average by more than your threshold.
A flag is a reason to look at a record again, not evidence of fuel theft. Heavier loads, hot weather, long idling or a missed full tank can all raise consumption.
Monthly fuel card audit checklist
The Fuel card audit sheet counts every flag type in the log and lists ten checks to run each month: unknown vehicles, missing odometers, readings that go backwards, liters above capacity, unusual consumption, refills outside working hours, several refills in a day, stations off the vehicle's route, card assignment and receipts. Each check has a status, an owner and a notes column, so the review leaves a record. It is a structured way to reconcile fuel spend against what the fleet actually did.
Idling log: estimating wasted fuel
The Idling sheet records long periods with the engine running and the vehicle stopped, such as waiting at a customer's site, loading or driver breaks. Minutes are calculated from start and end times, and liters are estimated from the idle rate in the row or the default on the Settings sheet, then costed at the price you set. Totals by reason show which situations to tackle first. To estimate idling for the whole fleet without logging each event, use the idling tab of the fleet fuel cost calculator.
Limits of a fuel log in Excel
The workbook is only as accurate as its entries. Missed full tanks, rounded odometer readings and late entries all reduce accuracy. Idling figures are estimates based on the rate you enter, not measurements. The template does not read fuel card files automatically or verify transactions with the station.