How this calculator works
The calculator converts the period you know into a yearly distance: 365 days, 52 weeks, 12 months, four quarters, two half-years or one year. Monthly and daily figures are the yearly distance divided by 12 and 365, not the original period scaled by an approximate month length. Fuel use is the yearly distance divided by fuel economy, and the cost is that volume times the pump price. The projection assumes the same distance every period, so it is a planning aid rather than a record of actual driving.
Formula
Annual distance = period distance x 365 for a daily figure, 52 for weekly, 12 for monthly, 4 for quarterly, 2 for half-yearly or 1 for yearly. Fuel = annual distance / fuel economy (km/L). Fuel cost = fuel x price per litre.
Worked example
Driving 50 km a day projects to 18,250 km a year. At 8 L/100 km the car uses 1,460 litres, costing $2,409 at $1.65 a litre. The monthly average is about 1,520.8 km and the daily average stays 50 km.
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Frequently asked questions
Why does a weekly figure use 52 weeks rather than 52.14?
A year has about 52.14 weeks, but 52 is the conventional planning figure and keeps the arithmetic simple. If precision matters, use the daily or yearly option and enter the exact distance.
Should I use my odometer or a typical week?
For an annual estimate, a full year of odometer readings is best. A single week or month can be unrepresentative because of a holiday, a move or a seasonal change in commuting.
Does the fuel cost include everything?
No. It covers fuel only. Insurance, maintenance, tires, parking and depreciation are separate, and the fuel price can change during the year.
Can I use miles and miles per gallon?
Yes. Choose miles for the distance and either US or imperial mpg for fuel economy. The page converts to kilometres and litres internally, then displays the result in the units you select.