Vehicle EconomicsFuel Cost Calculator
What you'll spend on gas this year, and how exposed that number is to gas-price swings.
Why this comes up
Fuel is one of the most volatile costs in owning a car, and it's the one people underbudget most often because the price at the pump moves for reasons that have nothing to do with the vehicle itself, a refinery outage or a geopolitical event can move your monthly cost more than a year of normal driving-pattern changes would. Most people know their loan payment to the dollar but only have a vague sense of their fuel spend. This engine gives you the annual figure at today's price and shows how much that number moves as gas prices swing, so the volatility is visible instead of just felt at the pump.
How we calculated this
Annual gallons is annual miles divided by MPG. Annual cost is gallons times your gas price. We sweep a range of nearby gas prices, from a dollar and a half below your entered price to a dollar and a half above, to show the sensitivity without you needing to re-run the calculator for each scenario.
Worked example, using this page's own defaults (12,000 miles, 30 MPG, $3.50/gal): annual cost comes to $1,400, or about $117/month. Run the calculator above with your own numbers.
What this means
- A lower-MPG vehicle is more exposed to gas-price swings in absolute dollars, the sensitivity table below shows exactly how much, useful context if you're weighing a less efficient vehicle against future price uncertainty, not just today's price.
- This annual figure feeds directly into True Cost of Car Ownership and Vehicle Cost Per Mile as one line item among several, run this first if you want to isolate the fuel piece before building the fuller picture.
- If your annual miles are only a rough guess, revisit this figure once you have a few months of real driving data, fuel cost is one of the more sensitive inputs to mileage assumptions.
Limitations
Gas price is your own entry, not a live feed, per this project's static-first privacy posture, and MPG is assumed constant regardless of season, driving style, or terrain, all of which move real-world fuel economy in practice. See Methodology.
Methodology
This engine is built on Vehicle Economics' fuel and charging cost model: your own miles, MPG or kWh, and rates converted directly to a dollar cost. See Methodology for the full detail.