Enter the distance, efficiency, and fuel price in the same selected system. The calculator does not fetch routes or live fuel prices.
Calculation details
Planning estimate only, not financial, tax, or legal advice. Verify assumptions and current rules before making decisions.
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What does this calculator estimate?
Fuel cost calculator: estimate gas money for any trip from distance, MPG, and fuel price, then split it between passengers. Free, editable rates, no signup.
Practical ways to reduce fuel costs
The average American driver spends roughly $3,000 per year on gas, according to the American Automobile Association. Several habits meaningfully cut that number: carpool or use public transit so fuel cost is shared across riders; drive a more fuel-efficient vehicle (a small sedan often costs about half the fuel of a very large SUV); and plan trips carefully so you drive shorter distances with fewer stops. Take steady-speed highways instead of ragged stop-and-go city streets where fuel economy suffers. Maintain your vehicle — properly inflated tires can improve fuel economy by up to 3%, fixing a faulty oxygen sensor can improve mileage by as much as 40%, and using the manufacturer's recommended motor oil grade can help 1–2%. These are practical levers anyone can apply, and the exact savings depend on driving patterns and vehicle condition.
What determines the price of fuel
Retail fuel prices are shaped by several forces beyond your control. Global oil prices — quoted for Brent and West Texas Intermediate (WTI) crude in US dollars per barrel — fluctuate constantly and retail prices track them closely. Governments influence price through fuel taxes and subsidies. Politics and international relationships can change supply and policy, and geography matters: regions near abundant supply tend to pay less than isolated areas. Natural disasters and severe weather can disrupt refineries and transport, briefly pushing prices up. Understanding these factors explains why gas prices vary so much by region and over time — and why your trip cost can change even with the same route and vehicle.
Fuel efficiency: MPG vs L/100 km
This calculator accepts two common fuel-efficiency systems. In miles-per-gallon (MPG) mode, divide the trip distance by the vehicle's MPG to get gallons used, then multiply by the price per gallon. In liters-per-100-kilometer (L/100 km) mode, multiply the distance by the efficiency and divide by 100 to get liters used, then multiply by the price per liter. Both give the same physical fuel consumption when you use consistent units — the key is entering distance, efficiency, and price in the same system, which is why this calculator keeps them together.
How this calculator works
Formula
MPG mode: gallons = total miles ÷ MPG. Metric mode: liters = total kilometers × L/100 km ÷ 100. Total distance applies the return-journey and trip-count choices. Fuel cost = fuel used × entered price, then cost per traveler divides equally.
Worked example
A 120-mile one-way journey, including the return, repeated twice is 480 miles. At 30 MPG and $3.50 per gallon, it uses 16 gallons and costs $56, or $14 each for four travelers.
Assumptions to verify
- Distance, efficiency, and fuel price use the same selected unit system.
- The entered efficiency is treated as constant across the trip.
- Tolls, parking, maintenance, charging, traffic, detours, and depreciation are excluded.
Frequently asked questions
Does this calculator fetch a route?
No. Enter the distance yourself; no map, location, or routing service is contacted.
Can I use liters per 100 kilometers?
Yes. Select metric mode and enter distance in kilometers, efficiency in L/100 km, and price per liter.
What costs are excluded?
The result covers entered fuel cost only and excludes tolls, parking, maintenance, depreciation, and other travel expenses.
How much does it cost to drive 100 miles?
At 30 mpg and $3.50 per gallon, 100 miles uses about 3.3 gallons and costs roughly $11.67. The exact amount depends on your vehicle's real-world efficiency and your local fuel price — enter your values into the calculator for a trip-specific estimate.
Does highway driving use less fuel than city driving?
Generally yes — steady highway speeds are far more fuel-efficient than stop-and-go city driving, which burns extra fuel accelerating from a standstill. This is one reason the calculator lets you set a single efficiency figure; for the most accurate result, use a number that reflects your typical driving mix.
Why does my fuel cost keep changing?
Fuel prices track global oil markets, taxes, regional supply, and weather disruptions, so the same trip can cost different amounts week to week. The calculator uses the price you enter, which lets you re-estimate as prices move.
Cite this tool
BoringToolsKit. “Fuel & Trip Cost Calculator.” boringtoolskit.com/fuel-trip-cost-calculator/ (reviewed August 2026). Free to reference in articles, syllabi, and answer posts with a link.
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