NumberTally Fuel & Trip Cost Calculator
How much will that drive really cost? Enter the distance, your vehicle’s fuel efficiency, and the fuel price to get the fuel needed, the trip cost, the cost per mile — and what you’d spend in a year.
Advanced options
MPG vs L/100 km
MPG (miles per gallon) is "distance per fuel" — bigger is better. L/100 km is "fuel per distance" — smaller is better. To convert: MPG = 235.215 ÷ (L/100 km). So 8 L/100 km ≈ 29.4 MPG. This calculator accepts both and converts behind the scenes.
Easy ways to cut fuel costs
Speed is the biggest lever: fuel economy typically drops sharply above 50–60 mph. Keeping tires at the recommended pressure, removing roof racks and excess weight, and combining errands into fewer trips each save a few percent. For commuters, the yearly-cost box shows what even a 2–3 MPG improvement is worth in dollars.
Frequently Asked Questions
How do you calculate trip fuel cost?
Divide the trip distance by your fuel efficiency to get gallons (or liters) needed, then multiply by the price per gallon. A 300-mile trip at 30 MPG uses 10 gallons — at $3.50/gal that’s $35.
How do I convert L/100 km to MPG?
Divide 235.215 by the L/100 km figure. For example, 7.5 L/100 km = 235.215 ÷ 7.5 ≈ 31.4 MPG.
What is a good fuel efficiency?
For US gasoline cars, roughly 25 MPG is average, 30+ is good, and 40+ is excellent (hybrids). Trucks and SUVs often sit in the high teens to low twenties.
Does the price per liter option handle conversions?
Yes — enter the price per liter and the calculator converts it to a per-gallon equivalent (× 3.78541) before doing the math, so mixing metric and US units just works.
Why does my real MPG differ from the sticker?
EPA ratings come from lab cycles. Short trips, cold weather, aggressive acceleration, idling, and speeds over ~60 mph all push real-world economy below the rating — often by 10–20%.