About Fuel Cost of Trip

Fuel Cost of Trip is run by a single independent builder as nine free fuel and running-cost calculators built around one idea: show the math, not just the number. Every tool states the formula it runs, works a real example through with the tool's own defaults, and shows exactly where a cited figure comes from -- exact unit-conversion constants, and the US Energy Information Administration's weekly gasoline price data where it's used as a starting point.

How the calculators work

Every calculator on this site -- fuel cost, trip cost, the fuel estimator, mpg, commute cost, cost per mile, EV charging cost, fuel savings and the unit converter -- routes distance, fuel-economy and price conversions through one shared set of functions, rather than each tool re-implementing its own unit math. Every formula is checked against a hand-derived expected value in the site's own test suite before it ships.

Where the figures come from

Unit-conversion constants (mile-to-km, US gallon, UK/imperial gallon) are exact definitional values from International Yard and Pound Agreement (1959); US NIST Handbook 44; UK Weights and Measures Act 1985, not rounded approximations. The optional fuel-price starting points come from the US Energy Information Administration, Gasoline and Diesel Fuel Update (week of September 14, 2026) -- the national average and the specific states and cities EIA itself reports weekly, never a full 50-state table presented as more complete than it is. The EV charging-loss default is a typical range from US DOE Alternative Fuels Data Center; typical AC (Level 1/2) charging loss range 10-15%. Every price field on every calculator defaults to what you type in -- the presets are a convenience, not an assumption.

What it doesn't do

These are estimates; real consumption varies with driving, load and conditions, and Fuel Cost of Trip isn't affiliated with any vehicle manufacturer, electric utility, or the US Energy Information Administration. Confirm any number here against your own fuel receipts or a full-to-full fill-up before relying on it for a real decision. See Terms.

Every calculator

• Fuel Cost Calculator -- Calculate how much fuel a trip needs and what it costs from distance, fuel economy in any unit (mpg US, mpg UK, L/100km or km/L) and your fuel price, with a round-trip toggle and a split-between-N-people option.
• Trip Gas Cost Calculator -- Estimate the gas cost for a multi-leg trip: add each leg's distance, include tolls, and split the total between passengers.
• Fuel Estimator -- Estimate how much fuel a distance will take, how many fill-ups you'll need for your tank size, and your driving range on a full tank.
• MPG Calculator -- Calculate your real fuel economy from a trip or a full-to-full fill-up: miles per gallon (US and UK), liters per 100 km, and km per liter.
• Commute Cost Calculator -- Calculate your weekly, monthly and yearly commute fuel cost from your one-way distance, days per week and fuel economy, with a second-vehicle comparison.
• Cost Per Mile Calculator -- Calculate your true cost per mile: fuel cost from your economy and price, plus optional annual maintenance and insurance spread across your yearly miles.
• EV Charging Cost Calculator -- Calculate the real cost to charge and drive an EV, accounting for charging efficiency loss, and compare it side by side with an equivalent gas car.
• Fuel Savings Calculator -- Compare two vehicles' annual fuel cost from their economy and your annual miles, and see how long a more efficient vehicle takes to pay back a higher price.
• Fuel Economy Converter -- Convert fuel economy between mpg (US), mpg (UK), liters per 100 km and km per liter instantly, with a reference table at common values.

Corrections

If a figure or citation here is wrong or out of date, email hello@fuelcostoftrip.com.