The average is 15,000 miles per year. Some lessors will vary the mileage by make (Ford, Toyota, etc.) of car and/or Manufacturers Suggested Retail Price (MSRP). In the majority of leases you are only charged at the end of lease term. However, your lease may be different. Read it carefully. The cents per mile over the allowed mileage will also vary by lessor. The average is $.15 per mile. It will be stated on your lease. 

This An Example Only: How does excess mileage work?
 

If you are allowed 15,000 miles per year and your lease term is two years then you can safely drive 30,000 miles (15,000 x 2 years = 30,000) with no excess mileage charge. But, if you drive 35,000 miles in two years then your excess mileage charge is 5,000 (35,000 - 30,000 = 5,0000 x $ .15 (if this is your lessors charge) = $750.00 (what you will owe in excess mileage charges). If you know you will drive more than the annual mileage allowed, have your lessor adjust the allowance before you sign the lease. They will do that but your monthly payment will increase because the dollar amount will be added to the total of lease payments. Some lessors will charge annual excess mileage charges if you early terminate. This combination of charges can easily get very expensive. Negotiate excess mileage charges for early termination out of your lease. This will be taken into consideration when your car is appraised for its current value. If your lessor will not waive early termination excess mileage charges then find another lessor.
 

 
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