This lease mileage calculator answers one question that a lease agreement makes surprisingly hard to answer for yourself: at the pace you are actually driving, will you finish the lease inside your mileage allowance, and if not, what will the excess cost? It compares miles driven against the allowance earned so far, projects that pace forward to the end of the term, and prices the overage at the per-mile rate you take from your own contract.
Arb Digital publishes free calculators like this because the numbers people most need are usually the ones nobody hands them. Lessors tell you the allowance and the per-mile charge at signing, then send a statement at the end. The pace in between — the part you can still change — is left to you.
What This Lease Mileage Calculator Does
You enter the lease term in months, how many months have elapsed, the annual mileage allowance, the odometer reading at delivery, the odometer reading today, and the excess mileage charge per mile from your contract. The calculator returns the projected excess charge at lease end, how far ahead or behind the allowance you are right now, your projected total mileage, the total allowance across the whole contract, and the mileage budget per month you have left if you want to land exactly on the allowance.
It publishes no rates and no allowances. The Federal Reserve's vehicle leasing resource notes that leases commonly cap annual driving and that excess mileage charges have historically fallen in a range of cents per mile, with higher charges on more expensive vehicles — but ranges are not your contract. Your allowance and your per-mile rate are written into your lease agreement, they vary by lessor, vehicle and term, and the contract is the only authority on them.
This is a different job from pricing the lease itself. Our car lease calculator works out the monthly payment from capitalised cost, residual and money factor; this page ignores the payment entirely and looks only at the mileage clause. If you are still deciding between leasing and owning, the lease vs buy calculator is the one that frames that choice.
How to Use It
- Get the term and allowance from the contract. Both are stated in the lease. If the lease gives a total mileage figure rather than an annual one, divide it by the term in years to get the annual number this tool expects.
- Enter the delivery odometer. A new vehicle usually has a small number of delivery miles on it. Those are typically excluded, which is why the field defaults to a low figure rather than zero — use whatever the delivery paperwork records.
- Enter today's odometer and the months elapsed. Both must describe the same moment, or the pace calculation will be wrong.
- Enter the excess mileage charge from your lease. Do not use a figure from an article, including this one. It is a contract term and it varies.
- Read the projected charge, then read the monthly budget figure — that is the number you can act on, because it tells you what driving pattern keeps you inside the allowance from here.
The Formula / How It's Calculated
Total contract allowance is annual allowance × (term ÷ 12). Allowance earned to date is annual allowance × (months elapsed ÷ 12). Miles driven is simply the difference between the two odometer readings. Your monthly pace is miles driven ÷ months elapsed, and the projected total at lease end is pace × term. Projected excess is that total minus the contract allowance, floored at zero, and the projected charge is the excess multiplied by the per-mile rate. The remaining monthly budget is (contract allowance − miles driven) ÷ months remaining.
Worked example, matching the defaults. A 36-month lease with a 12,000-mile annual allowance has a total allowance of 36,000 miles. Fourteen months in, the allowance earned is 12,000 × 14 ÷ 12 = 14,000 miles. The odometer has gone from 10 to 15,010, so 15,000 miles have been driven — 1,000 miles ahead of pace. The monthly pace is 15,000 ÷ 14 = 1,071.43 miles. Projected forward, 1,071.43 × 36 = 38,571.43 miles, which is 2,571.43 miles over the 36,000 allowance. At $0.25 per mile that is a projected charge of $642.86. With 21,000 miles of allowance left across 22 remaining months, the budget from here is 954.55 miles a month.
Why Straight-Line Projection Is Right — And When It Isn't
The projection assumes your future pace matches your past pace. That is the correct default because it is the only assumption supported by evidence you actually have, and it is the assumption a lessor would make if asked. But it is worth knowing exactly when it misleads.
It overstates future mileage if the driving that inflated your average has ended — a temporary commute, a house move, a year of long-distance family visits. It understates future mileage if a change is coming: a new job further away, a child starting at a school across town, a plan to take the car on a long summer trip. Neither case is a flaw in the arithmetic; it is a flaw in extrapolating from a period that was not representative.
The practical fix is to test both. Run the calculator with your real elapsed months for the honest baseline, then run it again with a hypothetical odometer that reflects the pace you expect to keep. If both projections land under the allowance, you can stop worrying. If they straddle it, the monthly budget figure is your operating limit, and it is worth tracking against it every month rather than every year. Our annual mileage calculator is useful here for turning a weekly driving pattern into an annual figure before you commit to a projection.
The Overage Number Is Not the Whole End-of-Lease Bill
Excess mileage is one line on an end-of-lease statement. It sits alongside excess wear and tear, a disposition fee where the contract specifies one, any outstanding payments, and in some contracts a charge for missing items such as a second key or the load cover. This calculator prices only the mileage line, because that is the only one that follows a clean formula.
That distinction matters when people compare quotes. A lease with a lower per-mile excess charge is not automatically cheaper at the end if its wear-and-tear standard is stricter or its disposition fee is higher. The Federal Reserve's vehicle leasing FAQ covers the end-of-term charges as a group and is a useful reminder that the lease-end settlement is made of several independent clauses, each written separately.
Options When the Projection Says You Will Go Over
This page does not tell you what to do, but it is worth knowing what levers exist so the number in front of you is actionable rather than just alarming. Reducing pace is the obvious one, and the monthly budget figure tells you precisely how much reduction is needed. Some lessors sell additional mileage during the term, usually at a rate below the end-of-term excess charge; whether that option exists, and at what price, is a question for your lessor and your contract, not something a calculator can answer.
Buying the vehicle at the end of the lease removes the mileage charge entirely in most contracts, because you are no longer handing back a car whose residual value the mileage has reduced — but that is a purchase decision with its own arithmetic, and the excess charge you avoid is only one input to it. Early termination is a third possibility and is generally expensive; the FAQ linked above sets out why.
What all three have in common is that they are cheaper to consider at month fourteen than at month thirty-five. The value of running this calculation early is entirely in the options it leaves open.
Business Mileage Is a Separate Calculation Entirely
If some of your driving is for business, it is easy to conflate two different mileage records. The lease cares about total miles on the odometer, no matter who or what they were for. A tax deduction cares about the business share of those miles and requires its own contemporaneous log. The two numbers come from the same odometer and are used for entirely different purposes, and mixing them up is a common error.
Our mileage deduction calculator handles the tax side. Keep it separate from this one: driving fewer business miles does not reduce your lease overage unless it reduces total miles, and claiming a deduction has no effect whatsoever on the lease allowance.
Costs the Mileage Clause Hides
Miles cost money beyond the excess charge. Fuel, tyres, servicing intervals and depreciation all scale with distance, and on a lease you are paying for the depreciation through the payment whether or not you exceed the allowance. If you are weighing a longer commute or a routine long trip, price the fuel with the fuel cost calculator and the whole journey with the commute cost calculator before treating the per-mile excess charge as the true cost of an extra mile. In most cases it is the smaller half.
Arb Digital maintains a large library of free, no-signup tools covering vehicles, money, home and work. Have a look, or get in touch if there is one you wish existed.
Browse Free Tools Contact Arb DigitalCommon Mistakes to Avoid
- Using a per-mile rate from an article instead of the contract — the charge is a negotiated lease term and differs between lessors, vehicles and terms.
- Starting the odometer at zero — delivery miles are usually excluded, and ignoring them slightly overstates your driving from the first month onward.
- Comparing miles driven against the full contract allowance — halfway through a lease you have earned half the allowance, not all of it, and that is the comparison that matters.
- Assuming under-mileage earns a refund — most contracts do not credit unused miles, so driving well under the allowance is money already spent in the payment.
- Treating the projection as a verdict — it extrapolates the pace you have set so far, and a single unrepresentative period at either end distorts it badly.
Related Free Tools From Arb Digital
Price the lease itself with the car lease calculator, frame the bigger decision with the lease vs buy calculator, and turn a driving pattern into a yearly figure with the annual mileage calculator. For the running costs behind each mile, the fuel cost calculator and commute cost calculator both help, and the mileage deduction calculator covers the tax side. The full free online tools hub lists everything else.
Frequently Asked Questions
In the lease agreement itself, normally in the end-of-term or excess mileage clause. It is a contract term set by the lessor and it varies by lessor, vehicle and term, which is why this page takes it as an input rather than publishing a figure.
Usually not. The odometer reading recorded at delivery is normally the baseline, and the allowance applies to miles added after that. Enter that delivery reading in the odometer-at-delivery field so the driven total is measured from the right starting point.
Ordinarily no. Excess mileage is typically settled at the end of the lease when the vehicle is returned and inspected, which is why the pace can drift for a long time without anyone flagging it. Your contract governs the timing.
Most leases do not refund unused mileage. The allowance is priced into the monthly payment, so mileage you do not use is generally not returned. Check your own contract, because a small number of agreements handle it differently.
It sometimes is, because some lessors sell additional mileage during the term at a lower rate than the end-of-term charge. Whether that option exists at all, and at what price, is entirely down to your lessor and your contract, so ask them rather than assuming.
Because it extrapolates from a short sample. Two months of unusual driving in a three-month-old lease dominates the average and swings the projected total wildly. The projection becomes far more stable once several months of ordinary driving are in the record.
Yes. The arithmetic does not care about the unit, so if your allowance, odometer and per-unit charge are all in kilometres the results are correct in kilometres. The unit selector only changes the wording on screen.
This tool performs arithmetic on figures you enter and is not financial, legal or contractual advice. Your lease agreement is the only authority on your allowance, your excess mileage rate and any end-of-term charges. Confirm anything that matters with your lessor.
