Which fuel efficiency unit should I use?
Use whichever your vehicle's manual or dashboard reports: MPG (US gallon) is common in the US, liters per 100km across most of Europe, and km per liter in parts of Asia and Africa. The calculator converts between them automatically.
Does this account for traffic, terrain, or driving style?
No. It applies your entered fuel efficiency evenly across the whole distance. Real-world fuel use varies with traffic, load, terrain, and driving style, so treat the result as an estimate.
What if I don't know my exact fuel efficiency?
Check your vehicle's manual, dashboard trip computer, or manufacturer specifications. Many manufacturers publish combined city and highway figures that work well as an estimate here.
Is my trip and price information sent anywhere?
The calculation runs in a background process on your own device and nothing you enter is stored.