Lease Mileage Calculator
A lease charges for extra miles one of two ways: an overage charge for every mile past your allowance, collected when you turn the car in, or a lower price per mile if you buy the extra miles when you sign. Example: 12,000 expected excess miles at a $0.25 overage charge cost $3,000 at lease end, while buying the same miles upfront at $0.15 a mile costs $1,800, saving $1,200. (Full worked examples below.)
On typical leases the overage charge often runs from $0.15 to $0.30 per mile, and extra miles bought at signing are usually priced below it. Both numbers are printed in your lease agreement; enter yours, not the typical ones.
| Total mileage allowance | |
|---|---|
| Total miles you expect to drive | |
| Expected excess miles | |
| Cost of paying the overage at lease end | |
| Cost of buying those miles upfront | |
| Savings from the better choice | |
| Breakeven driving level |
How the comparison works
Every variable in this calculator comes from your lease or from your own driving:
Miles allowed per year is the mileage allowance in your lease, commonly 10,000 or 12,000 miles a year. Lease term is the length of the lease in years. Total mileage allowance is the two multiplied: allowed miles per year × term in years. It is the total that counts at turn-in, not the miles in any single year.
Miles you expect to drive per year is your honest estimate of your driving. Total miles you expect to drive is that estimate times the term. Expected excess miles is the expected total minus the allowance, and never below zero: max(0, expected total − total allowance).
Overage charge per mile is the fee your lease sets for each excess mile, charged once at lease end. Upfront price per mile is what the leasing company charges to raise your allowance at signing, per extra mile. The two costs are the same pile of miles at two different prices:
cost of paying the overage = excess miles × overage charge per mile
cost of buying upfront = excess miles × upfront price per mile
Because both costs multiply the same excess miles, the lower per-mile price wins on every mile, and the size of the win is excess miles × (higher price − lower price). The breakeven driving level is the allowance itself: at or below it there are no excess miles and both choices cost $0. Above it, only the price gap matters.
Worked example 1: buying miles upfront wins
A 3 year lease allowing 10,000 miles a year, for a driver who expects 14,000 miles a year. The lease charges $0.25 a mile in overage; extra miles at signing cost $0.15 a mile.
| Total mileage allowance (10,000 × 3 years) | 30,000 miles |
|---|---|
| Total miles expected (14,000 × 3 years) | 42,000 miles |
| Expected excess miles | 12,000 miles |
| Paying the overage (12,000 × $0.25) | $3,000.00 |
| Buying upfront (12,000 × $0.15) | $1,800.00 |
| Savings from buying upfront | $1,200.00 |
Worked example 2: paying the overage wins
A 3 year lease allowing 12,000 miles a year, for a driver who expects 12,500 miles a year. This lease charges $0.20 a mile in overage, but its extra miles at signing are priced at $0.30 a mile, above the penalty itself.
| Total mileage allowance (12,000 × 3 years) | 36,000 miles |
|---|---|
| Total miles expected (12,500 × 3 years) | 37,500 miles |
| Expected excess miles | 1,500 miles |
| Paying the overage (1,500 × $0.20) | $300.00 |
| Buying upfront (1,500 × $0.30) | $450.00 |
| Savings from paying the overage | $150.00 |
Buying upfront only wins when its per-mile price beats the overage charge. When a lease prices signing miles above its own overage fee, there is nothing to buy: just drive and pay the smaller bill at the end.
What changes the answer most
The gap between the two per-mile prices. Miles only scale the result; the winner is decided entirely by which price is lower. A $0.10 gap over 12,000 excess miles is $1,200. How sure you are about your mileage. The two choices are not equally risky. Miles bought upfront are paid for whether you drive them or not, and unused prepaid miles are typically not refunded at lease end. The overage charge bills only the miles you actually drove. If your estimate might come in low because of a job change, a move, or a second car, the overage can be the safer choice even when its rate is higher: run this calculator at your low estimate as well as your expected one and compare. Your expected miles estimate itself. Underestimating is the expensive mistake either way, because every mile you did not plan for lands at the overage rate.
FAQ
Where do I find my overage charge and the upfront mile price?
Both are in your lease agreement: the overage charge in the mileage or excess wear section, and the price of extra miles in the allowance terms or an addendum. If you are still shopping, ask the dealer for both numbers in writing before you sign, and ask what a higher allowance does to the monthly payment.
What if I drive less than my allowance?
Nothing is owed, and unused standard allowance miles have no value at turn-in. If you bought extra miles upfront and did not use them, that money is typically gone; check your agreement for any refund provision before counting on one.
Does going over in one year matter if I am under in another?
Most leases measure the total allowance at turn-in, so a heavy year can be offset by a light one. Your agreement controls; this calculator works on totals for that reason.
Can I buy more miles after the lease starts?
Some leasing companies sell additional miles partway through a lease, usually at a price between the signing price and the overage charge. It is the lessor's option, not a right, so if you are running over, ask early rather than at turn-in.
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