MPG (miles per gallon) and KPG (kilometres per gallon) are two ways to express the distance a vehicle travels on a mile of gas. Converting between the two requires simple arithmetic, and there are websites that can perform these calculations for you. Generally, the higher the miles or kilometres per gallon, the more efficient the vehicle.
Write down the MPG. For example, the car may get 5 MPG.
Multiply MPG by 1.61 to obtain KPG. In the example, multiply 5 MPG by 1.61 to obtain 8.05 KPG.
Check your math by going to the Online Conversion website (see Resources). Click "miles/gallon" in the left column and "km/gallon" in the right column. In the blank text field, type in the number in MPG, in the example this is 5. Click "Convert." The converter tool should show 8.05 KPG.
There are duplicate MPG and KPG entries in the scroll-boxes at the Online Conversion site, one pair for United States MPG and KPG values and another pair for United Kingdom MPG and KPG values. Be sure to select the appropriate pair for your conversion.