Method
US mpg = miles traveled ÷ refill gallons; other units convert from exact distance and volume factors.
Everyday worksheet
Fill-to-Fill Gas Mileage Calculator
Calculate fuel economy from odometer distance and refill volume, then compare US mpg, Imperial mpg, km/L and L/100 km.
The calculation runs locally. Results include the intermediate values, unit conversions and assumptions needed to audit the answer.
Method, assumptions and practical use
How the Fill-to-Fill Gas Mileage Calculator works
US mpg = miles traveled ÷ refill gallons; other units convert from exact distance and volume factors. Inputs stay in this browser, and the result table exposes conversions and assumptions for independent checking.
Interpret the result
The second refill volume estimates fuel used since the first consistent fill point.
Check the assumptions
One tank is an estimate; pump shutoff, fill level and short distances can dominate error. Average multiple tanks for a better measure.
Local calculation
Everything runs in this browser. Inputs are not sent to an external calculator.
Rounding
Displayed values may be rounded for readability while calculations use full floating-point precision unless the tool explicitly uses exact integers.
Scope
One tank is an estimate; pump shutoff, fill level and short distances can dominate error. Average multiple tanks for a better measure.
Simple by design
Three steps to a clearer number.
Enter your details
Use realistic values in each field. You can change them anytime.
Calculate instantly
The formula runs locally, so there is no account or waiting time.
Use the result
Treat the answer as a practical estimate for your next decision.