Fuel Cost Calculator
Estimate fuel, total trip cost, and each traveler's average from your distance, economy, and entered price.
Manual estimate: enter a distance, fuel economy, and price. This calculator does not look up routes, vehicles, stations, or live prices.
Estimated whole trip
Fuel cost result
- Fuel needed
- Fuel cost
- Other costs
- Average / traveler
- Cost / distance
Normalized calculation receipt
Money rounds half up to cents from unrounded values. Fuel shows up to 3 decimals; cost per distance shows 4.
Copy manually
Private calculation: values stay in this tab. They are not added to the URL, storage, network requests, cookies, or analytics. Analytics receives only fixed unit-mode, trip-style, action, and error categories.
Fuel cost formulas
US fuel = trip miles ÷ US MPG. Multiply the US gallons by the entered USD price per US gallon. For metric inputs, fuel = trip kilometers × L/100 km ÷ 100, then multiply the liters by the entered USD price per liter.
Return over the same distance multiplies distance by two before either formula. Optional other costs are entered for the whole trip and are added once. Total trip cost equals fuel cost plus those other costs. Cost per distance divides that total by the full one-way or round-trip distance.
Worked US example
A 300-mile trip at 25 US MPG uses exactly 12 US gallons. At $3.50 per US gallon, fuel costs $42.00, or $0.1400 per mile. A return over the same distance is 600 miles, uses 24 US gallons, and costs $84.00. Split among four travelers, the average is $21.00 each. Add $12.00 of whole-trip other costs and the total becomes $96.00, or $24.00 each; the $12.00 is not doubled.
Worked metric example
A 500-kilometer trip at 8 L/100 km uses exactly 40 liters. At $1.50 per liter, fuel costs $60.00, or $0.1200 per kilometer. Metric mode takes a consumption rate in liters per 100 kilometers; it does not treat that value as kilometers per liter.
US gallons, Imperial gallons, and estimates
US mode means US customary liquid gallons and US MPG. NIST distinguishes the US gallon from the larger Imperial gallon, so an Imperial MPG figure cannot be entered as US MPG without conversion. This page does not offer an Imperial mode.
Your actual fuel use can differ with traffic, speed, weather, load, terrain, idling, and vehicle condition. Use the economy and pump-price estimate that fits your trip. This browser-only arithmetic tool does not create a route, find a station, fetch a live price, identify a vehicle, or produce an official travel quote.
Input and rounding rules
Use complete ASCII decimals with no more than six digits after an optional decimal point. Distance accepts 0.01 through 1,000,000. US fuel economy accepts 0.1 through 1,000 MPG; metric consumption accepts 0.01 through 1,000 L/100 km. Fuel price accepts $0 through $1,000 per active volume unit, and other whole-trip costs accept $0 through $1,000,000. Each field is limited to 80 raw characters before whitespace is trimmed, travelers must be a whole number from 1 to 100, and values outside these limits fail closed without keeping an earlier result.
Decimal inputs are parsed into exact rational values with BigInt arithmetic. Money rounds half up to cents from the unrounded rational, fuel displays up to three decimals, and cost per mile or kilometer displays four decimals. A positive amount smaller than a display unit is labeled with a less-than value instead of appearing as zero.
Frequently asked questions
How do I calculate fuel cost for a trip?
In US mode, divide trip miles by US MPG to get US gallons, then multiply by your entered USD price per US gallon. In metric mode, multiply kilometers by L/100 km, divide by 100, and multiply the liters by your entered price per liter.
How does the round-trip option work?
Return over the same distance doubles the entered distance once. Fuel use and fuel cost follow that doubled distance. Optional other costs are whole-trip amounts, so they are added once and never doubled.
Can I split the estimate among travelers?
Yes. Enter 1 to 100 travelers. The calculator divides the unrounded total by that count, then rounds the displayed average half up to cents. It is an equal average rather than an individual payment schedule.
Is US MPG the same as Imperial MPG?
No. This page uses miles per US liquid gallon. An Imperial gallon is larger, so an Imperial MPG value is not interchangeable with US MPG. Convert it before using US mode.
Does this calculator use live gas prices or plan a route?
No. You supply distance, fuel economy, and price. The calculator does not use location, maps, route generation, station data, live prices, traffic, toll lookup, or a vehicle database.