Fuel Cost Calculator
Calculate exactly how much fuel your trip or annual driving will cost. Enter distance, MPG, and gas price — get total cost, cost per mile, and gallons needed instantly.
miles
MPG
$/gal
Enter your values above to see the results.
Tips & Notes
- ✓Use the current price at your local pump — not last week's price. Fuel prices change daily and vary by up to $0.50/gallon between stations in the same city.
- ✓Use your real-world MPG, not the EPA sticker estimate. Track it yourself: fill up, reset the trip odometer, drive until the next fill-up, then divide miles by gallons added.
- ✓Highway driving is 20-30% more fuel-efficient than city driving. For mixed trips, estimate a blended MPG closer to your city figure if you expect significant stop-and-go traffic.
- ✓For round trips, enter the total distance (both directions). A 200-mile one-way trip = 400 miles total — a mistake that throws off the fuel budget by 100%.
- ✓Keeping tires properly inflated and avoiding aggressive acceleration can improve real-world MPG by 5-15%, meaningfully reducing fuel cost over any trip longer than 100 miles.
Common Mistakes
- ✗Using the EPA sticker MPG instead of observed MPG — real-world efficiency is typically 10-20% lower due to traffic, AC use, cargo weight, and driving style.
- ✗Entering one-way distance for a round trip — always enter total miles for the full journey, not just one direction.
- ✗Using last week's gas price — prices change daily. Check a current local price (GasBuddy, your gas station app) for an accurate fuel cost estimate.
- ✗Mixing unit systems — if distance is in kilometers and efficiency is in MPG, results will be wrong. Use consistent units throughout.
- ✗Ignoring fuel grade — premium fuel costs $0.20-0.40 more per gallon than regular and is only required for certain high-compression engines. Using premium in a regular-fuel engine provides no benefit.
Fuel Cost Calculator Overview
Fuel cost is the single largest ongoing operating expense for most vehicle owners — typically $1,200 to $3,500 per year depending on vehicle type and driving habits. The difference between an accurate fuel budget and a rough guess compounds over months of driving, making precise calculation genuinely valuable for both trip planning and annual budgeting.
Trip fuel cost formula:
Fuel Cost = (Distance ÷ MPG) × Price per Gallon | Gallons Used = Distance ÷ MPG
EX: Road trip 450 miles, vehicle gets 28 MPG, gas price $3.60/gal → Gallons = 450 ÷ 28 = 16.07 gal → Cost = 16.07 × $3.60 = $57.86 → Cost per mile = $3.60 ÷ 28 = $0.129/mileAnnual fuel cost formula:
Annual Fuel Cost = (Annual Miles ÷ MPG) × Price per Gallon
EX: 15,000 miles/year, 32 MPG, $3.50/gal → Annual gallons = 15,000 ÷ 32 = 468.75 → Annual cost = 468.75 × $3.50 = $1,640.63Annual fuel cost by vehicle type — 15,000 miles/year at $3.50/gallon:
| Vehicle Type | Typical MPG | Gallons/Year | Annual Fuel Cost | Cost per Mile |
|---|---|---|---|---|
| Large SUV / Truck | 16 MPG | 938 gal | $3,281 | $0.219 |
| Midsize SUV | 26 MPG | 577 gal | $2,019 | $0.135 |
| Midsize Sedan | 32 MPG | 469 gal | $1,641 | $0.109 |
| Compact Car | 38 MPG | 395 gal | $1,382 | $0.092 |
| Hybrid | 52 MPG | 288 gal | $1,010 | $0.067 |
| Plug-in Hybrid (mixed) | 65 MPGe | 231 gal | $808 | $0.054 |
| MPG | L/100km | Annual Cost (15k mi, $3.50) |
|---|---|---|
| 20 MPG | 11.76 L/100km | $2,625/year |
| 25 MPG | 9.41 L/100km | $2,100/year |
| 30 MPG | 7.84 L/100km | $1,750/year |
| 35 MPG | 6.72 L/100km | $1,500/year |
| 40 MPG | 5.88 L/100km | $1,313/year |
| 50 MPG | 4.70 L/100km | $1,050/year |
Frequently Asked Questions
Divide the total trip distance by your MPG to get gallons needed, then multiply by the current gas price. Example: 450-mile trip in a car getting 30 MPG = 15 gallons needed. At $3.60/gallon, that is $54 in fuel. For a round trip, double the one-way distance first. This calculator does all of this automatically — enter distance, MPG, and gas price and the result appears instantly.
Most gasoline passenger cars average 25-35 MPG combined city/highway. Compact sedans (Honda Civic, Toyota Corolla) achieve 32-40 MPG. Midsize SUVs average 22-28 MPG. Full-size trucks and large SUVs average 15-22 MPG. Hybrids achieve 40-60 MPG. Plug-in hybrids depend on battery charge. Electric vehicles measure efficiency in MPGe, not MPG. Track your own MPG over several fill-ups for the most accurate number.
Several driving habits meaningfully reduce fuel consumption. Maintaining steady highway speeds using cruise control improves MPG by 7-14% compared to variable throttle. Accelerating gradually from stops instead of aggressively reduces consumption by 10-30% in city driving. Keeping tires inflated to the recommended PSI improves MPG by 1-3%. Removing unnecessary cargo (roof racks, heavy items) reduces weight and drag. Combined, these habits can add 15-25% to effective fuel economy.
At 15,000 annual miles and $3.50/gallon: a 25 MPG car uses 600 gallons per year at a fuel cost of $2,100. A 35 MPG car uses 429 gallons per year at a fuel cost of $1,500. The difference is $600 per year — about $50 per month. Over 5 years of ownership, the more fuel-efficient vehicle saves approximately $3,000 in fuel alone, not counting reduced maintenance from a less-stressed engine.
At 15,000 miles/year in a 30 MPG vehicle, you use 500 gallons annually. A $0.50/gallon price increase adds $250/year in fuel cost; a $1.00 increase adds $500/year. This is why fuel-efficient vehicles provide more protection against rising gas prices — the same $1.00 increase adds only $429/year for a 35 MPG car versus $750/year for a 20 MPG vehicle. The higher your MPG, the less you are exposed to gas price volatility.
Divide 235.21 by your MPG to get L/100km. A 30 MPG vehicle uses 235.21/30 = 7.84 L/100km. A 40 MPG hybrid uses 235.21/40 = 5.88 L/100km. European fuel economy ratings are typically in L/100km — lower numbers are better. The inverse relationship means a small MPG improvement at low efficiency (say 20 to 22 MPG, saving 1.07 L/100km) saves more fuel than the same improvement at high efficiency (40 to 42 MPG, saving 0.28 L/100km).