CalcToolVault

Fuel Cost Calculator

Calculate the fuel cost of a trip or a year of driving, and compare two vehicles side by side.

Your details

mi
mpg
$/gal

Compare a second vehicle

mpg
$/gal

This calculator runs entirely on your device. Nothing you enter is uploaded, stored, or sold. How this works

Total fuel cost

$2,105.77

576.9 gallons at $3.65 per gallon

Save these results

Includes your inputs, the full breakdown, and every row of the table.

Cost per mile

$0.140

Gallons used

576.9

Fuel economy (metric)

9.0 L/100km

11.1 km/L

Monthly cost

$175.48

If this is an annual distance

$0$865$2k$3k$3k23456
26.0 mpg38.0 mpg
Annual cost
Breakdown
Vehicle 1 fuel cost
$2,105.77
Vehicle 2 at 38.0 mpg
$1,440.79
Vehicle 2 saves
$664.98

What this means

  • Over five years the more efficient vehicle would save roughly $3,325 at these prices and distance.
  • Real-world economy typically runs 10-15% below EPA estimates for highway-heavy driving and worse in cold weather or heavy city traffic.

How the fuel cost calculation works

Fuel cost is distance divided by fuel economy times price per gallon. The subtlety is that miles per gallon is a nonlinear measure: improving from 15 to 20 mpg saves far more fuel than improving from 40 to 50 mpg over the same distance, even though the second looks like a bigger jump.

That is why cost per mile is the more useful comparison metric. It converts everything to a single number you can multiply by your actual annual mileage, and it works identically for gasoline, diesel, and electric vehicles.

Frequently asked questions

How do I convert MPG to L/100km?

Divide 235.215 by the MPG figure. 30 mpg is about 7.8 L/100km.

Is premium fuel worth it?

Only if your engine requires it. In vehicles designed for regular, premium provides no measurable power or economy benefit — it simply costs more per gallon.

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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.