Fuel Cost Calculator
Calculate trip fuel cost online free. Enter distance, fuel efficiency (MPG or L/100km), and fuel price to get fuel needed (gallons or liters), total cost, and cost per mile or km. Toggle between US (MPG) and metric (L/100km) systems. 100% browser-based, no signup.
Trip Fuel Estimate
Enter distance, efficiency, and fuel price and instantly get the total fuel needed and total trip cost. Works for daily commutes, road trips, or fleet budgeting.
US + Metric Modes
A single toggle switches between US (miles, MPG, gallons, $/gal) and metric (km, L/100km, liters, $/L). Your input values are kept separate so switching never loses them.
Cost per Mile / Km
Beyond the bottom-line cost, the calculator returns cost per mile (US) or cost per km (metric) — perfect for mileage reimbursement, ride-share pricing, or comparing vehicles.
100% Private
All calculations run in your browser. No trip data, no fuel prices, no vehicle info is uploaded. No signup and no daily limit.
How is the fuel needed for a trip calculated?
In US mode: fuel (gallons) = distance (miles) ÷ MPG. In metric mode: fuel (liters) = distance (km) × (L/100km ÷ 100). The total cost is then fuel needed × fuel price, and cost per mile/km is total cost ÷ distance.
What is the difference between MPG and L/100km?
MPG (miles per gallon) is fuel efficiency expressed as distance-per-volume — higher is better. L/100km (liters per 100 km) is volume-per-distance — lower is better. The metric system is used in most of the world; MPG is used in the US and UK. The calculator handles both with a toggle.
How do I switch between US and metric units?
Use the toggle at the top of the calculator. Switching changes the unit labels and the math applied; your US and metric inputs are kept separately, so toggling back and forth never loses what you typed.
What is "cost per mile" and why does it matter?
Cost per mile (or per km) is total fuel cost ÷ distance. It is the standard figure used for mileage reimbursement (e.g. the US IRS rate), ride-share and delivery pricing, and comparing the running cost of two vehicles. Lower is cheaper to operate.
Does the calculator include wear-and-tear or depreciation?
No — this calculator is for fuel cost only. For the full "cost to drive" you would add per-mile maintenance, depreciation, insurance, and registration on top. Fuel is usually the largest variable cost, but not the only one.
Ready to use the Fuel Cost Calculator?
Free, no signup, no watermark. 100% browser-based. Your data never leaves your device.
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