AutoMath
Financing

Lease Mileage Overage Calculator

The lease payment isn't the whole bill. If your driving runs past the mileage cap, the excess charge lands at turn-in — find out how big it'll be while you can still do something about it.

Your numbersSaved on this device only
The lease
The rates
⚠️ Projected excess-mileage bill

$2,250

9,000 mi over the 36,000 mi allowance

Prepaying saves $900
Buying the overage up front is cheaper than paying at turn-in. Lock it in early.
Total allowance
36,000 miover the whole lease
Projected miles
45,000 mi
Monthly budget
1,000 mimiles/mo to stay under
Prepaid cost
$1,350buy the overage now

What this computes

A lease's mileage allowance is pooled across the whole term, and it's easy to forget until the bill arrives. This projects your total miles against the allowance, the excess-mileage charge it triggers at lease-end, and whether buying extra miles up front is the cheaper move. It also gives you a monthly mileage budget so you can course-correct mid-lease.

The math

total allowance = annual allowance × (term / 12)
projected miles = your annual miles × (term / 12)
over miles      = max(0, projected − total allowance)
end charge      = over miles × excess rate
prepaid cost    = over miles × buy-up rate

The allowance pools: a 36-month, 12,000-mile lease is 36,000 miles total — a good year and a bad year average out. What matters is the total over the term, not any single year.

The average driver covers 13,500 miles a year. The average lease allows 12,000. The gap is a bill almost nobody budgets for.

How to use this

  1. Be honest about your driving. Use last year's actual miles, not the number you wish were true.
  2. Read the excess rate off your contract. It's a fixed per-mile figure, usually 15-30¢.
  3. Check whether prepaid miles are offered, and at what rate — enter it to compare against the end charge.
  4. Watch the monthly budget. If you're already over your per-month allowance, the projection is a warning, not a guess.

Prepaid vs pay-at-end

  • Prepaid is cheaper per mile — but only worth it if you actually drive the miles, because it's usually non-refundable.
  • Pay-at-end is risk-free if you're unsure: you only pay for miles you really drove, just at the higher rate.
  • Buying the car waives the charge entirely. If you're far over, the buyout can beat returning it and eating the overage.

What this calculator doesn't model

  • Excess wear-and-tear charges — dings, tires, and curb rash are billed separately at turn-in.
  • Disposition fees due when you return the car.
  • Mileage banking programs some brands offer to roll unused miles forward.
  • A mid-lease swap or early termination, which changes the miles you're responsible for.

Frequently asked questions

How much is the excess-mileage charge on a lease? +
Typically 15-30¢ per mile, set in your contract — luxury brands run higher. On a lease 9,000 miles over the cap at 25¢/mile, that's a $2,250 bill due when you turn the car in. The rate is fixed in the lease, so you can compute the bill the moment you know your driving pace.
What's the standard lease mileage allowance? +
Most leases offer 10,000, 12,000, or 15,000 miles per year, and the allowance is pooled over the whole term — a 36-month, 12,000-mile lease gives you 36,000 miles total, not a hard 12,000 each year. The average US driver covers about 13,500 miles a year, so a 12,000-mile lease puts a typical driver over the cap.
Can I buy extra lease miles in advance? +
Often yes. Many leasing banks sell additional miles up front at a lower per-mile rate than the end-of-lease excess charge — say 15¢ instead of 25¢. If you already know you'll go over, prepaying locks in the cheaper rate. The catch: prepaid miles are usually non-refundable, so don't over-buy.
What if I drive under the mileage allowance? +
You don't get money back for unused miles — they simply expire. That's the argument for not over-buying allowance or prepaid miles: unused miles are wasted money, while going over is a known per-mile charge. Aim to match the allowance to your honest driving, not your optimistic one.
Does the overage charge apply if I buy the car at lease-end? +
No. If you exercise the buyout and purchase the car at its residual, the excess-mileage charge is waived — you own the miles. That can flip the math: a driver far over the cap sometimes comes out ahead buying the car rather than returning it and paying the overage. Check it with the lease buyout calculator.
How accurate is the projection? +
It assumes your future driving matches the annual figure you enter, scaled across the full term. Real life varies — a new commute or a move changes everything. Re-run it whenever your driving changes and watch the monthly mileage budget so you can course-correct before the bill is locked in.

Related calculators

  • Lease Payment — the monthly number this bill sits on top of.
  • Lease Buyout — buying the car waives the overage; is the residual a deal?
  • Lease vs Buy — high mileage is a classic reason buying wins.
  • Cost Per Mile — what each of those extra miles really costs you to drive.

More on this: will you blow your lease mileage?, and heading into the last months of a lease, the lease-end decision tree.

AutoMath is an educational tool. The projection depends entirely on the mileage and rates you enter and is not a statement of what you'll owe.