Lease Mileage Overage Calculator
Your allowance, your real mileage, and the two prices per mile
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Educational estimate only. Confirm the assumptions, current rules, fees, and rounding that apply to your situation before making a decision.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter the miles a year your lease allows and the lease term, both from the contract.
- 02
Enter the miles you expect to drive a year. The quickest estimate is your odometer: miles driven so far, divided by months so far, times twelve.
- 03
Enter the charge per mile over the allowance at turn-in, in cents, from the contract.
- 04
Enter the price per mile the lessor quotes for extra miles bought up front, how many extra miles a year you would buy, and any refund per unused pre-bought mile. Leave the refund at 0 if the contract gives none.
- 05
Read the turn-in bill, the cost of prepaying instead, the saving, and the break-even mileage, then check the table to see how the answer changes if your estimate is off by a few thousand miles a year.
Formula
Allowance for the term = miles allowed a year × (term in months ÷ 12). Excess miles = miles you expect a year × term in years − that allowance, never below zero. Turn-in bill = excess miles × the overage charge. Prepay cost = miles bought × the prepaid price − the refund × any pre-bought miles not driven + the overage charge × any excess beyond the miles bought. Break-even excess = miles bought × (prepaid price − refund) ÷ (overage charge − refund), which exists only when the overage charge is above both the prepaid price and the refund. Break-even miles a year = the yearly allowance + break-even excess ÷ term in years.
Example
A 36-month lease allowing 12,000 miles a year, driven 15,000 miles a year, with a 25-cent overage charge. That is 9,000 miles over the 36,000-mile allowance and a turn-in bill of $2,250, or about $63 for every month of the lease. The lessor sells extra miles up front at 15 cents with no refund, so buying 3,000 a year, 9,000 in all, costs $1,350 and saves $900. The catch is the break-even: prepaying only pays if you drive more than 13,800 miles a year. At 13,500 miles a year the turn-in bill would be $1,125 against the same $1,350 up front, and a driver who stayed inside the allowance would have spent the $1,350 for nothing.
Definitions
- Mileage allowance
- The miles a lease lets you drive without charge, stated as a yearly figure and usually measured as a total for the term at turn-in.
- Excess mileage charge
- The per-mile fee in the contract for every mile over the allowance, billed when you return the car. The Federal Reserve's leasing guide cites 10 to 25 cents a mile or more.
- Pre-purchased miles
- Extra miles bought when the lease is signed, or sometimes mid-lease, usually at a lower price per mile than the turn-in charge.
- Break-even mileage
- The yearly mileage at which buying extra miles up front and paying the overage at turn-in cost the same. Above it prepaying wins; below it paying at turn-in does.
- Turn-in
- Returning the leased car at the end of the term, when the lessor inspects it and bills any excess mileage, excess wear and the disposition fee.
Good to know
How the allowance was priced into your payment
A mileage allowance is not a courtesy added to a lease. It is one of the inputs that set the payment. The lessor forecasts the car's value at the end of the term, and a car returned with 45,000 miles is worth less than the same car returned with 30,000. So a higher allowance means a lower residual, more depreciation charged through the payment, and a higher monthly bill. Leases are commonly written at 10,000, 12,000 or 15,000 miles a year, and the difference between those tiers is priced like everything else in the lease: as depreciation spread over the term, plus the finance charge on it. That is why extra miles bought at signing are usually cheaper per mile than the charge at turn-in. A mile bought up front is priced as expected depreciation. A mile billed at turn-in is priced as a penalty, set high enough that the lessor does not lose money on a heavily driven car. The Federal Reserve's consumer leasing guide puts excess-mileage charges at 10 to 25 cents a mile or more, and notes that negotiating a higher limit at signing often costs less than paying for excess miles at the end. On the default figures the gap is ten cents a mile, 25 cents at turn-in against 15 cents up front. Across 9,000 excess miles, that is the $900 difference between a $2,250 turn-in bill and $1,350 paid at signing. The same logic runs in reverse for a low-mileage driver. An allowance far above what you drive is depreciation you paid for and never used, and unused allowance miles are generally not refunded.
Prepaying is a bet on your own odometer
Buying miles up front trades a certain cost now for an uncertain one later, and the break-even mileage says how confident you need to be. If you buy extra miles and then drive fewer of them than you bought, the unused miles are wasted unless the contract refunds them. If you drive more, you pay the turn-in charge on the rest. Setting the two costs equal gives the excess at which prepaying and paying at turn-in cost the same: the miles bought times the prepaid price less any refund, divided by the turn-in charge less that refund. On the default figures, 9,000 miles bought at 15 cents with no refund break even at 5,400 excess miles, which on a 36-month lease is 1,800 a year over a 12,000-mile allowance. Drive more than 13,800 miles a year and prepaying wins. Drive less and it loses. The table on the page shows how quickly the verdict flips. At 13,500 miles a year the turn-in bill would be $1,125, less than the $1,350 paid up front. At 16,500 it would be $3,375, against $2,475 for prepaying plus the overage on miles the prepayment did not cover. The asymmetry is worth noticing. Overestimating your mileage costs the prepaid price on each unused mile. Underestimating it costs the turn-in charge on each extra mile, which is higher. So when the estimate is genuinely uncertain, buying somewhat fewer miles than your best guess limits the damage in both directions. A refund policy changes the bet entirely: if unused miles come back at close to their price, prepaying generously costs almost nothing.
Checking your pace, and the ways out when you are over
The cheapest time to deal with excess mileage is early, and the only tool needed is the odometer. Divide the miles driven so far by the months elapsed and multiply by the lease term. If that projection is above the total allowance, you know the size of the problem while there is still time to act. Most leases state the allowance as a yearly figure but measure it once, at turn-in, against the total for the term, so a heavy year can be offset by lighter ones later. There are several ways to respond. The first is to drive the lease car less, if the household has a second vehicle that can take the long trips. The second is to buy miles mid-lease, which some lessors allow at a price between the signing rate and the turn-in charge, although the option often closes well before the lease ends. The third is to avoid turn-in altogether. An overage is only billed when the car goes back to the lessor. Buy the car out at its residual, or trade it at a dealer that pays off the lease, and no mileage charge is ever billed. The miles still cost something, because a car with high mileage is worth less, but the market's discount for extra miles is usually smaller than a contract charge of 25 cents each on a car that is otherwise in demand. The lease buyout calculator prices that route, counting the turn-in charges as a cost the buyout avoids. The last option is a lease transfer, which hands the remaining lease to someone else, but the miles already driven go with it, so a careful taker will price them in.
Refunds, unused miles, and choosing the next allowance
A lease's mileage terms work in one direction by default. Drive over and you pay; drive under and you usually get nothing back. The Federal Reserve's leasing guide notes that some lessors refund the charge for extra miles bought at signing if you do not drive them, but only if the lease agreement says so, and many contracts do not. That refund is the difference between prepaying as insurance and prepaying as a gamble. Without it, the default figures put $1,350 at risk: a driver who bought 9,000 miles and then stayed inside the original allowance would have paid that sum for nothing. The same logic applies to the base allowance. A driver who picks a 15,000-mile lease and drives 10,000 has paid, through every monthly payment, for depreciation on miles that never happened, and at turn-in there is typically no credit for them. The practical conclusion is to choose the allowance from evidence rather than hope. Last year's odometer readings, the length of the commute, and any change coming, such as a new job, a move or a child starting school across town, are better guides than the lowest payment on a dealer's worksheet. For a driver near the boundary between two tiers, the arithmetic on this page answers the choice. Take the extra monthly cost of the higher tier, multiply by the term, divide by the extra miles it allows, and treat the result as a prepaid price per mile. Then compare it with the turn-in charge and your honest estimate of how far you will drive. When a lease is already signed, the question narrows to the one this page answers: what the extra miles cost at turn-in against paying for them now.
Frequently asked questions
How much does it cost to go over the miles on a lease?
The per-mile charge in your contract times every mile over the allowance for the whole term. The Federal Reserve's consumer leasing guide puts these charges at 10 to 25 cents a mile or more. On the default figures, driving 15,000 miles a year on a 12,000-mile, 36-month lease puts you 9,000 miles over, and at 25 cents a mile the bill at turn-in is $2,250.
Is it cheaper to buy extra miles up front?
Per mile, usually, but only if you drive them. On the defaults, 9,000 extra miles bought at 15 cents cost $1,350 against a $2,250 turn-in bill, a $900 saving. But with no refund for unused miles, prepaying only pays if you drive more than 13,800 miles a year. At 13,500 the turn-in bill would be $1,125, less than the $1,350 paid up front.
What happens to pre-bought miles I never drive?
That depends entirely on the contract. The Federal Reserve's leasing guide notes that some lessors refund charges for purchased miles you do not use, but only if the lease says so. Without a refund, every unused mile is money spent for nothing. On the default figures, driving only the allowance would leave the whole $1,350 wasted.
Can I avoid the overage charge at turn-in?
Yes, by not handing the car back. If you buy the car out at the residual, or trade it at a dealer that pays off the lease, no mileage charge is billed. The extra miles show up instead as a lower market value, which is usually a smaller hit than the per-mile charge. The lease buyout calculator prices that route.
Are lease miles counted each year or over the whole lease?
Most leases state the allowance as miles a year but measure it once, at turn-in, against the total for the term. A 12,000-mile, 36-month lease allows 36,000 miles in all, so a light first year offsets a heavy third. This calculator counts miles the same way, across the whole term.
Can I buy more miles in the middle of a lease?
Some lessors sell additional miles partway through a lease, usually at a price between the signing rate and the turn-in charge. Ask before the last months of the lease, because the option often closes well before turn-in. If it is offered, enter that mid-lease price in the prepaid field and the miles you still need.