Fuel Cost Calculator
$0.00 total fuel cost
How the Fuel Cost Is Calculated
This calculator uses the standard trip fuel-cost formula: divide the total distance by your vehicle's fuel efficiency (miles per gallon) to get gallons consumed, then multiply that by the price per gallon. In short, fuel cost = (distance ÷ MPG) × price per gallon. If you toggle "round trip," the distance you entered is simply doubled before that calculation runs.
Where to Get an Accurate MPG Figure
The single biggest lever on accuracy here is the MPG value, not the math. A window-sticker EPA combined rating is a reasonable starting point, but real-world mileage often runs 10-20% lower depending on speed, terrain, cargo, and climate control use. If you want a number based on your own vehicle's actual recent fill-ups rather than an estimate, use the gas mileage calculator to derive it from odometer and pump data, then plug that figure in here.
Fuel Cost vs. Reimbursement
This tool estimates what you'll actually spend on gas for a trip — it is not the same as a business mileage reimbursement rate, which bundles in depreciation, insurance, and maintenance rather than just fuel. If you're calculating a reimbursable or tax-deduction amount instead of out-of-pocket fuel spend, use the mileage calculator instead.
Frequently Asked Questions
How do I calculate the fuel cost of a road trip?
Divide the total trip distance by your vehicle's fuel efficiency in miles per gallon to get gallons needed, then multiply that by the current price per gallon. For example, a 300-mile trip at 28 MPG and $3.50/gallon uses about 10.7 gallons, costing roughly $37.50.
Should I use my car's EPA rating or real-world MPG?
Real-world MPG is more accurate for cost estimates, since EPA combined ratings are lab-tested and often run 10-20% higher than actual highway driving with AC, cargo, or hills. If you don't know your real MPG, use the gas mileage calculator to derive it from a recent fill-up before estimating cost here.