Mileage Calculator – MPG, Fuel Economy And Trip Cost
This mileage calculator gives you several ways to understand how efficiently your car, motorcycle, van or fleet uses fuel. You can calculate MPG, km/L and L/100km from a single fill, estimate trip cost from distance and fuel price, calculate distance from fuel used and track running cost per mile or kilometer.
Core Mileage And Fuel Economy Formulas
The tools on this page are built on a few keyationships:
- MPG (US) = miles driven ÷ gallons of fuel used
- km/L = kilometers driven ÷ liters of fuel used
- L/100km = 100 × liters ÷ kilometers
- Trip fuel cost = fuel used × fuel price per unit
- Cost per mile = total trip cost ÷ miles
The converter tab uses the standard approximation:
L/100km ≈ 235.21 ÷ MPG (US)
That means higher MPG values correspond to lower L/100km values, which is why one region prefers “more is better” and the other prefers “less is better.”
Using The MPG And Trip Cost Tabs
The MPG tab is usually the best place to start after a fill-up. You enter the distance you drove since the last fill and the fuel required to fill back to the same level. The calculator converts units if needed and returns MPG, km/L and L/100km, plus optional cost per distance if you also enter fuel cost.
The trip cost tab works the other way around. You supply a planned distance, your typical fuel economy and the price of fuel per gallon or per liter. The tool estimates the fuel you will use and the trip fuel cost. It also shows the implied fuel economy in all three units so you can quickly compare figures from different sources.
Distance From Fuel Used And Trip Logs
When you know how much fuel you have but not exactly how far that will take you, the distance tab helps. You enter fuel amount, fuel economy and optional price. The calculator estimates how far you can travel in both miles and kilometers and what that fuel is worth at the given price.
The trip log tab is designed around odometer readings. You record starting and ending reading for a trip or a week of commuting and add the fuel required to refill. The tool calculates distance, MPG, km/L, L/100km and, if you include cost, cost per mile and per kilometer. This is useful for tracking improvements over time after maintenance or driving style changes.
Cost Per Mile Andated Driving Tools
The cost-per-mile tab looks at fuel from a budgeting point of view. Instead of focusing on MPG, it shows how much you actually spent per mile, per kilometer and per 100 km. You can combine this with other transportation and finance tools on this site, such as a Fuel Cost Calculator or a Gas Mileage Calculator when you want to compare different routes, vehicles or commuting options.
Gas Mileage Calculator
Frequently Asked Questions
Common questions MPG, L/100km, trip cost accuracy, and how to track mileage for personal or business use.
Small changes in fill level, traffic conditions, weather, tire pressure and driving style can all affect MPG from one fill-up to the next. Looking at several tanks and averaging the results gives a more accurate picture of your true long-term fuel economy than a single data point.
MPG (miles per gallon) measures how far you can drive on one gallon of fuel — so higher numbers mean better fuel economy. L/100km (liters per 100 kilometers) measures how much fuel you use to travel 100 kilometers — so lower numbers are better. The converter tab on this page lets you move between MPG, L/100km and km/L for easy comparison.
Estimates depend entirely on the inputs you provide. Real-world results can vary because of terrain, driving speed, traffic patterns, passenger load, tire pressure and weather conditions. These calculators are best used for planning and comparison rather than guaranteed outcomes.
Yes. Many users track multiple vehicles by keeping separate logs for each one, recording odometer readings, dates, fuel fills and receipts. This calculator helps estimate cost-per-mile and trip expenses, but for tax deductions or reimbursement you should keep detailed records in addition to the calculator outputs.