How do you calculate your cars gas mileage?

(1) fill your tank all the way, (2) set your trip odometer to 0 or write down the present mileage, (3) drive, (4) fill your tank all the way again, (5) check your trip odometer or compare the current mileage to the old mileage number to determine the number of miles you drove, (6) divide the number of miles by the number of gallons of gas it took to fill your tank the second time. The resulting number is how many miles your car got to the gallon of gas.

Fill up your gas tank, then reset the trip odometer. Next time you get gas, fill the tank again, and divide the amount of gas you got into the miles you traveled since you last filled it up. The mileage varies a bit depending on certain factors such as city vs. highway driving.

Fill your car completely with gas and write down the mileage or set your trip. When you fill it up again write down the mileage and devide it by the gallons that it took to fill it back up again.

Example: mileage was 13000 when you filled it up the first time, you drove 300 miles and filled it back up again. It took 15 gallons to fill it up again. Take 300 devided by 300 and you got 20 miles per gallon.

fill your tank completly and reset your trip counter (or record the milage you are at) next time you fill your tank write down how much gas you put in and the milage you are at then.

then take the number for the milage and divide it by the number for the gas.

so like, you went 300 miles on ten gallons, 300/10 is 30 so 30 miles to the gallon

Reset your trip odometer when you fill up. Drive around and the next time you get gas see how many miles you've driven and divide by the number of gallons of gas it takes to fill your car.

easiest way is what they said but if you don't want to run your tank empty.

1. Reset your tripometer, and fill your tank full

2. Drive as much as you want

3. Fill up with gas

4. Divide the number of miles on your tripometer by the number of gallons of gas that you put in

Find out how many gallons your tank holds. Fill it up all the way, and reset your tripodemer.

See how many miles you drove until it gets down to empty. Then divide the number of miles by the number of gallons!

fill the tank full --write down the milage at that point--- when close to empty then filll again--- take that milage --subtract the start milageand that answer you dive by the gallons

i.e 85000start 85475 end 475 miles per tank 12 gallons= 39.58 mpg

Take the miles driven divided by fuel used (amount put inyour next fill). Simple math. It's not exact, but a good measure.