When you rent a SnappCar, you get a certain amount of kilometers per rental day of your rental period you are allowed to drive without an extra charge. The amount of free kilometers is set by the owner, as is the price a renter pays per kilometer when the renter drives more than the free amount. The total amount of free kilometers for a rental is calculated by multiplying the number of days the rental period is long by the number of free kilometers per day. More information about the pricing of extra kilometers can be found here.