RoadCost makes every mile understandable
Simple, useful driving economics without opaque recommendations.
Open guide →TRUST / METHODOLOGY
Calculation methodology
The formula should never be a black box.
Gasoline
Gallons = miles ÷ MPG. Fuel dollars = gallons × price per gallon. Trip energy and toll totals use full numeric precision until displayed.
Electric
Battery kWh = miles × kWh per 100 miles ÷ 100. Purchased kWh = battery kWh ÷ charging efficiency. A user-entered tariff mix estimates electricity cost.
Assumptions and freshness
The default gas price is $3.995/gal (EIA Gasoline and Diesel Fuel Update, U.S. regular, week of Nov 9, 2026) and the default home electricity rate is the EIA U.S. residential average for July 2026 ($0.1831/kWh). Other defaults (MPG, distance, DC fast-charging rate, budget items) are illustrative scenarios. Local prices vary: enter your own prices and vehicle efficiency. Distance comes from Google Maps routing when available; otherwise it is entered manually. This build does not retrieve local fuel prices or live charging data.
Useful primary data sources
For current U.S. petroleum prices consult the U.S. Energy Information Administration. For individual car energy efficiency consult EPA FuelEconomy.gov. This build does not automatically synchronize these sources; enter the relevant published numbers manually.
Geography and policy
Initial tools use U.S. units: miles, USD, gallons and kilowatt-hours. Toll values are user-provided; no guaranteed real-time station or road-toll coverage exists in this version.
Keep exploring
Fuel cost calculator
Get gallons, price per mile and cost per person from your own numbers.
Open calculator →EV road trip charging cost
Model a realistic charging mix instead of pretending every kWh costs the same.
Open calculator →