Know what the trip costs before you’re standing at the pump. The Gizmo 421 Fuel Cost Calculator takes your distance, your vehicle’s efficiency, and today’s gas price, and tells you exactly how many gallons (or liters) you’ll burn and what the whole trip will cost — split per person if you’re carpooling.
Nothing leaves your browser — the math happens right here on the page.
The calculator updates live as you type, handles both US and metric units (miles per gallon or liters per 100km), and splits the total across any number of people. It also flags suspicious inputs — enter 5 mpg in US mode or 25 L/100km in metric and it gently suggests you double-check, because nobody’s truck is that thirsty. Estimates assume steady highway-style driving; real-world consumption rises with city driving, mountains, A/C, and your personal acceleration enthusiasm.
How do I calculate fuel cost for a trip? Divide distance by your MPG to get gallons, multiply by price per gallon — that’s it, and the calculator does the metric version too. How much gas for 300 miles at 25 mpg? 12 gallons — about $42 at $3.50/gal. Does it handle L/100km? Yes, switch to metric mode and distance over 100 times the consumption figure gives your liters. Can I split costs for a carpool? Enter the number of people and the per-person share appears automatically.