Fuel Cost Calculator

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Calculate the exact fuel cost for any trip in seconds. Enter your distance, vehicle fuel efficiency, and local fuel price. Toggle round trip, add weekly trips for monthly and annual projections, or compare two vehicles to see which one saves more over time.

How to Use

01

Select your unit system: Imperial (MPG, miles, gallon) or Metric (L/100km, km, liter).

02

Enter your trip distance, vehicle fuel efficiency, and price per fuel unit.

03

Optionally check Round Trip to double the distance automatically.

04

Enter trips per week to generate monthly and annual cost projections.

05

Enable vehicle comparison to compare two vehicles side by side with a savings breakdown and cost chart.

How Fuel Cost Is Calculated

For imperial units, fuel used in gallons equals distance in miles divided by MPG. For metric, fuel used in liters equals distance in kilometers divided by 100, then multiplied by the L/100km rating. In both cases, total cost equals fuel used multiplied by the price per unit. Enabling round trip doubles the distance before any calculation. Monthly projection multiplies daily cost (trip cost times trips per week divided by 7) by 30. Annual projection uses the same daily cost multiplied by 365.

Worked Example

  1. Trip: 50 miles | MPG: 30 | Price: 3.50 per gallon
  2. Fuel used = 50 / 30 = 1.667 gallons
  3. Trip cost = 1.667 x 3.50 = 5.83
  4. Round trip doubles distance to 100 miles: 3.333 gallons, 11.67 total
  5. At 5 trips per week: daily cost = 5.83 x 5 / 7 = 4.16, monthly = 124.82, annual = 1,519
  6. Vehicle 2 at 45 MPG: trip cost = 50 / 45 x 3.50 = 3.89, saving 1.94 per trip or about 520 per year

When to Use This Calculator

  • Estimating the cost of a road trip before you leave
  • Comparing fuel costs between your current car and a potential new one
  • Budgeting your monthly commute or weekly driving expenses
  • Evaluating whether a more fuel efficient vehicle is worth the upgrade
  • Calculating how much a round trip costs versus a one way journey
  • Comparing petrol, diesel, or different fuel grades at different prices

Important Note

Fuel efficiency figures are averages and vary with driving style, road conditions, vehicle load, speed, and temperature. Real world consumption often differs from manufacturer quoted MPG or L/100km ratings. Fuel prices fluctuate frequently, so use current local prices for the most accurate estimates.

High vs. Low Fuel Efficiency Over Time

A 45 MPG hybrid costs about 33% less to fuel per mile than a 30 MPG sedan
Switching from 8 L/100km to 5 L/100km saves 37.5% on every trip
Higher efficiency vehicles reduce fuel budget impact during price spikes
Large or sporty vehicles at 15 to 20 MPG can cost two to three times more per trip
Aggressive driving can reduce real world efficiency by 10 to 30 percent
Short cold start trips consume disproportionately more fuel per kilometer

Key Features

Unit System Toggle

Switch between Imperial and Metric instantly. Labels, placeholders, and calculations adjust automatically.

Round Trip and Weekly Projections

Double your distance with one checkbox and project monthly and annual costs from your weekly trip frequency.

Vehicle Comparison

Enter a second vehicle's efficiency and fuel price to see a side by side table and bar chart of trip, monthly, and annual cost differences.

Visual Cost Chart

Bar chart comparing fuel costs between two vehicles, showing either trip or annual totals depending on your inputs.