Fuel Cost & Trip FAQs
How fuel cost math works, unit conversions, and real-world accuracy.
FuelTrip runs every trip calculation on your device — nothing is sent or stored.Quick answers on estimating fuel and EV charging cost for road trips, commutes, and carpooling.
How the fuel cost math works
The calculator divides your distance by your vehicle's MPG to get gallons, then multiplies by price per gallon. Kilometres and L/100 km are normalized to the same basis first, and a round trip simply doubles the distance and cost.
MPG vs L/100 km
US MPG, UK MPG, and L/100 km are just different ways to say the same efficiency. Use the MPG converter to switch between them; lower L/100 km is better, higher MPG is better.
Why real cost differs
Lab MPG overstates real driving. Air conditioning, cold weather, hills, and stop-and-go traffic typically trim 10–20% off the sticker number, so pad your estimate.
Splitting cost with passengers
Set the passenger count on any calculator and the result shows each person's share of the fuel bill — handy for long carpool trips.
Frequently Asked Questions
Is the fuel cost estimate exact?
It is exact for the numbers you enter, but real driving varies with traffic, weather, and price swings, so treat it as a planning figure.
Which efficiency number should I use?
Use your car's combined MPG (or L/100 km) from the window sticker; for a personal figure, track a few fill-ups and use your average.
Do you store my trip details?
No. Every calculation runs on your device and nothing is uploaded or saved.
Can I compare gas vs electric?
Yes — use the fuel calculator and the EV charging calculator with the same distance to compare.