Last updated: March 2026
What Is a Gas Cost Calculator?
A gas cost calculator is a tool that estimates the fuel expense for any trip based on three inputs: distance, vehicle fuel efficiency (MPG), and the current price of gasoline. It instantly shows you how much you'll spend on gas, how many gallons you'll need, and the cost per mile of your drive.
Whether you're planning a daily commute, a weekend getaway, or a cross-country road trip, knowing your fuel cost upfront helps with budgeting and route planning. The average US gas price is $3.50 per gallon in 2026, but prices can swing by a dollar or more depending on your state and local market conditions.
How to Calculate Fuel Cost
Step 1: Know your distance. Use your car's trip odometer, Google Maps, or this calculator to determine the total miles you'll drive. If it's a round trip, double the one-way distance.
Step 2: Find your vehicle's MPG. Check your owner's manual, the sticker on the driver's door jamb, or look it up at fueleconomy.gov. Keep in mind that real-world MPG is typically 10–15% lower than EPA estimates, especially in city driving.
Step 3: Check the gas price. Use a gas price app or simply check the pump price on your last fill-up. Prices vary significantly by region — California and Hawaii tend to be highest, while Gulf Coast states are typically cheapest.
Step 4: Run the math. Divide distance by MPG to get gallons needed, then multiply by price per gallon. A 250-mile trip at 28 MPG and $3.50/gallon: 250 ÷ 28 = 8.93 gallons × $3.50 = $31.25.
Key Features
Vehicle presets for instant estimates. Select from six common vehicle types — compact car, midsize sedan, SUV, pickup truck, hybrid, and EV — to instantly populate realistic MPG values. No need to look up your car's fuel economy if you know the general category.
Road trip mode with multiple stops. Planning a trip with overnight stops or detours? Add as many waypoints as you need. The calculator shows per-leg cost breakdowns and a running total, so you can budget each segment separately or see the total picture.
Gas vs. electric comparison. Curious whether an EV would save you money? The comparison tab shows side-by-side trip costs for a gas vehicle and an electric vehicle, plus an annual savings projection based on your driving habits.
Metric and imperial support. Toggle between miles/MPG/gallons and kilometers/L per 100km/liters. Americans drive an average of 13,500 miles per year, and the average car gets 25.4 MPG — but this calculator works for drivers anywhere in the world.
Gas vs Electric: Cost Comparison
The cost gap between gas and electric vehicles continues to widen in favor of EVs for fuel costs alone. At national averages of $3.50 per gallon for gas and $0.15 per kWh for electricity, a gas car averaging 25 MPG costs about $0.14 per mile while a typical EV at 0.30 kWh per mile costs about $0.045 per mile — roughly 68% less.
Over 13,500 annual miles, that translates to approximately $1,890 for gas versus $607.50 for electricity, a potential annual savings of $1,282.50. However, the total cost of ownership includes factors beyond fuel: higher upfront purchase price for EVs, lower maintenance costs (no oil changes, less brake wear), battery degradation, and varying electricity rates depending on whether you charge at home or at public stations.
Home charging at off-peak rates can bring EV costs as low as $0.03 per mile in many markets, while DC fast charging at public stations can cost $0.08–$0.12 per mile — still cheaper than gas but with a narrower margin. Use the Gas vs Electric tab above to run the numbers with your specific rates.
Frequently Asked Questions
How do you calculate gas cost for a trip?
Divide your trip distance by your vehicle’s MPG to get gallons needed, then multiply by the current gas price. For example, a 300-mile trip in a car getting 25 MPG at $3.50/gallon: 300 ÷ 25 = 12 gallons × $3.50 = $42.00 in fuel cost.
What is the average MPG for cars in the US?
The average fuel economy for new cars in the US is about 25.4 MPG as of 2026. Compact cars average 30–35 MPG, midsize sedans 26–30 MPG, SUVs 20–25 MPG, and pickup trucks 16–20 MPG. Hybrids typically achieve 45–55 MPG.
How much does it cost to drive 1,000 miles?
At the US average of 25.4 MPG and $3.50/gallon, driving 1,000 miles costs about $137.80. In a fuel-efficient hybrid at 48 MPG, the same trip costs roughly $72.90. In a pickup truck at 18 MPG, expect to pay around $194.40.
Is it cheaper to drive or fly?
For solo travelers, flying is often cheaper for distances over 500 miles. But driving becomes more economical with multiple passengers since fuel cost is shared. A 500-mile drive at $3.50/gallon and 25 MPG costs about $70 — split between 4 people, that’s just $17.50 each.
How does driving speed affect fuel cost?
Fuel efficiency drops significantly above 50 mph. Each 5 mph over 50 costs roughly $0.20–$0.30 more per gallon equivalent. Driving 75 mph instead of 65 mph can reduce fuel economy by 15–20%, adding $15–$25 to a 500-mile trip.
How much cheaper is an electric car to operate?
Electric vehicles cost roughly 60–70% less per mile to operate than gas cars. At national averages ($0.15/kWh electricity vs. $3.50/gallon gas), an EV costs about $0.045/mile compared to $0.14/mile for a 25 MPG gas car. That’s approximately $1,280 in annual savings over 13,500 miles.