How to use this calculator
Estimate fuel spending for a journey. Enter distance (miles), fuel economy (us mpg), price (usd / us gallon). The result updates when you change an input. To compare two sets of inputs, save scenario A, then enter the second set; the result panel shows the difference.
Formula and limits
Cost = distance ÷ fuel economy × price per US gallon. Does not include tolls, vehicle wear, or changing fuel prices.
Worked example
The following example uses the calculator’s starting values. It is an illustration of the method, not a recommended target.
| Input | Example value |
|---|---|
| Distance (miles) | 300 |
| Fuel economy (US mpg) | 30 |
| Price (USD / US gallon) | 3.5 |
Estimated fuel cost: $35.00
Fuel needed: 10 US gallons
Interpreting your result
Use quantities from your actual bill, journey, or schedule. Defaults show how the tool works. Rounding and changing conditions can create a small difference from the final real-world amount.
Comparing alternatives
Save the first result as scenario A, then change one input. The comparison shows the numeric difference; it does not label either result as better. Choose inputs that describe realistic alternatives. Values shown on screen are rounded, so calculations from rounded intermediate results may differ slightly.