What This Calculator Works Out
A lease is not a loan for the whole asset. You are renting the part of its value that disappears while you have it, and paying a finance charge on the money tied up in the meantime. That is why lease payments are lower than loan payments on the same car, and it is also why the numbers are harder to compare between offers.
The page opens on an ordinary set: a $34,500 asset with a $19,200 residual value, leased for two years and six months at 7.4%. That works out to $678.60 a month. Across 30 payments you hand over $20,357.85, of which $15,300 is the depreciation you are paying for and $5,057.85 is finance charges — just under a quarter of everything you pay.
The second tab runs the calculation backwards. Enter a monthly payment you have been quoted and it solves for the rate hidden inside it, which is the number dealers are least likely to volunteer.
How a Lease Payment Is Built
Two components, added together.
Monthly payment = amount financed × i ÷ [ 1 − (1 + i)−n ]
i = annual rate ÷ 1200 · n = months in the term
The first line is the part people miss. You are not financing the full asset value, and you are not simply financing the difference between the asset and the residual either. You are financing the asset value less the present value of the residual, because that residual is not received until the end of the term.
From there it is ordinary amortisation. Each month the finance charge is calculated on the value still outstanding, the rest of the payment reduces that value, and by the final payment the outstanding value has fallen to exactly the residual. That last point is not an approximation — the schedule on this page lands on the residual to within a fraction of a cent, which is the check that the maths is right.
At a 0% rate the whole thing collapses to something obvious: depreciation divided by the number of months. On the opening figures that would be $510.00 against the $678.60 at 7.4%, which is a clean way to see exactly what the finance charge is costing you.
Which Tab to Use
- Fixed Rate — you know the rate or money factor and want the payment. Use it to check a quote, to see what a different term does, or to work out what you can afford before you walk in.
- Fixed Pay — you have been given a monthly payment and want the rate behind it. Enter the asset value, the residual and the term alongside the payment, and the calculator works backwards.
The second one is the reason to bookmark this page. Lease advertising is built around the monthly payment because it is the number that feels manageable, and two offers with the same payment can carry very different rates once the residual and term differ. Reducing each offer to a single percentage makes them comparable in a way the payment never will.
Solving backwards has no clean formula — the rate sits inside an exponent — so it is found numerically. Because the payment rises steadily as the rate rises, the search cannot get stuck or return a false answer.
What Each Input Means
- Asset value — the agreed value of the thing being leased. In a car deal this is the capitalised cost after any negotiation, trade-in or rebate, not the sticker price.
- Residual value — what it is contracted to be worth at the end. Set by the leasing company, usually as a percentage of the original value, and not something you get to choose.
- Lease term — in years and months. The months box handles the odd terms leasing companies favour, such as 27 or 39 months.
- Interest rate (Fixed Rate) — the annual rate. If you were given a money factor instead, multiply it by 2,400.
- Monthly payment (Fixed Pay) — the principal-and-finance payment. Exclude sales tax, registration and any fees quoted separately, or the rate will come out far too high.
Residual Value Does the Heavy Lifting
Of everything on the form, the residual moves the payment more than anything except the asset value itself, and it is the input people understand least.
Hold the opening figures and change only the residual. At $19,200 the payment is $678.60. At $15,000 it becomes $806.47. That is nearly $128 a month, roughly $3,800 over the term, from one number you never negotiated.
The logic is straightforward once stated: you pay for the fall in value, so the less it falls, the less you pay. This is why a car with a reputation for holding its value can lease for less than a cheaper car that depreciates hard, and why the same model can lease very differently in two years when the leasing company revises its residual assumptions.
It also explains the counter-intuitive part of leasing. A high residual is good for your payment but it means you are paying a lot to buy the car at the end if you want to. A low residual makes the lease expensive and the buyout cheap.
Money Factor, and the Shortcut That Is Slightly Wrong
Leasing quotes its interest rate as a money factor, a small decimal that looks nothing like a percentage.
0.00308 × 2400 = 7.4%
Always convert. A money factor carries no intuition, which is arguably the point of quoting it that way; 7.4% instantly invites the question of whether a car loan would be cheaper.
Most lease guides also give a shortcut for the payment: depreciation divided by the term, plus asset value plus residual multiplied by the money factor. It is worth knowing that this is an approximation, not the formula. On the opening figures it produces $675.58 against the exact $678.60. Three dollars a month is not much, but the gap widens with the rate and the term, and it is the wrong tool for comparing two offers that are close. This calculator does the full amortisation rather than the shortcut.
Reading the Payment Schedule
The schedule underneath splits every payment into its finance charge and its depreciation, with a Monthly and an Annual view.
Watch the finance column fall. The charge is calculated on the value still tied up in the asset, and at the start that is nearly all of it, so early payments are finance-heavy. As the value amortises down, the same payment shifts steadily toward depreciation. The payment itself never changes.
The chart beside it plots the value falling from the asset value to the residual, with the residual drawn as a dashed line. That line is the whole point of a lease: everything above it is what you pay for, everything below it is somebody else's problem.
What Is Actually Negotiable
- Asset value — very negotiable. This is the capitalised cost, and it is the ordinary price negotiation. Every dollar off it reduces both the depreciation and the finance charge.
- Money factor — often negotiable, and often marked up over the rate the leasing company actually set. Ask for the buy rate.
- Residual value — not negotiable. It is set by the leasing company. You can still use it: a model with a strong residual is cheaper to lease.
- Term — your choice, with a trade-off. Stretching the opening figures from 30 months to 36 drops the payment from $678.60 to $593.62, and you pay for more months at a lower residual.
- Fees — acquisition and disposition fees are sometimes negotiable and are frequently rolled into the capitalised cost, where they quietly earn finance charges.
Leasing Against Buying
The honest comparison is not payment against payment, because a lease payment covers less.
Leasing costs you the depreciation plus the finance charge and leaves you owning nothing. Buying with a loan costs you the whole asset plus interest and leaves you owning something with the residual value still in it. Over a single short term, leasing is usually cheaper per month and more expensive per mile of ownership. Over many years of repeated leases against one long-held purchase, buying almost always wins on cost alone.
Where leasing genuinely competes is when the residual is high, the money factor is subsidised, or the asset is something you actively want to replace every few years. For the loan side of that comparison, the Auto Loan Calculator gives the other half of the numbers, and the Auto Lease Calculator adds the tax and fee handling specific to U.S. vehicle leases.
What This Calculator Leaves Out
- Taxes. Sales tax on leases is handled differently in nearly every state — some tax the monthly payment, some the whole capitalised cost.
- Fees. Acquisition, disposition and documentation fees are not modeled unless you fold them into the asset value yourself.
- Down payments and trade-ins. Subtract them from the asset value before entering it.
- Mileage and wear charges. End-of-lease penalties depend entirely on the contract.
- Early termination. Ending a lease early is usually expensive and is not modeled here.
- Security deposits and multiple-security-deposit rate reductions.
For the rate on a conventional loan rather than a lease, see the Interest Rate Calculator; for how an asset loses value over time, the Depreciation Calculator.
Frequently Asked Questions
How is a lease payment calculated?
A lease charges you for the value the asset loses while you have it, plus a finance charge on the money tied up in it. Take the asset value, subtract the present value of what it will be worth at the end, and spread that over the term the way a loan is amortised. On this page's opening figures — a $34,500 asset with a $19,200 residual over 30 months at 7.4% — that comes to $678.60 a month.
What is residual value and why does it matter so much?
It is what the asset is expected to be worth when the lease ends, and it is the single biggest lever on your payment. You are only paying for the fall in value, so a higher residual means less to pay for. Dropping the residual in the opening example from $19,200 to $15,000 pushes the payment from $678.60 to $806.47 — nearly $128 a month, with nothing else changed. A residual around 55% of the asset value over two and a half years is typical for a car.
What is a money factor and how does it relate to the interest rate?
Money factor is how leasing quotes an interest rate, and it looks small because it is the annual rate divided by 2,400. A money factor of 0.00308 is a 7.4% rate; multiply by 2,400 to convert. It is worth doing that conversion every time, because 0.00308 does not feel like anything while 7.4% is immediately comparable to a car loan.
The dealer only gave me a monthly payment. Can I work out the rate?
That is what the Fixed Pay tab is for. Enter the asset value, the residual and the term alongside the payment you were quoted, and the calculator solves backwards for the rate that makes those numbers work. It is the most useful thing on this page, because a payment on its own hides whether you are being charged 4% or 14%.
Why does the usual money-factor shortcut give a different answer?
The shortcut taught in most lease guides — depreciation divided by the term, plus asset plus residual multiplied by the money factor — is an approximation. It gives $675.58 on this page's opening figures where the exact amortisation gives $678.60. About three dollars a month, and it grows with the rate and the term. The shortcut is fine for a quick sanity check and not for comparing offers.
Can a lease have a negative interest rate?
It can, and this calculator will tell you when it does. If the payments add up to less than the asset actually loses in value, the implied rate is below zero — the manufacturer is subsidising the lease to move stock. It is a real and occasionally excellent deal, so the figure is shown rather than hidden.
Why is more of my early payment going to the finance charge?
Because the finance charge is calculated on the value still tied up in the asset, and at the start that is nearly the whole thing. As the value amortises down toward the residual, the finance portion shrinks and more of the same payment goes to depreciation. The payment never changes; the split does, exactly as with a loan.
Does this work for equipment and property leases too?
Yes. The arithmetic is the same whatever is being leased: an asset value, a residual, a term and a rate. Vehicle leases are just the most common consumer case. What the calculator does not cover is the extras — acquisition and disposition fees, taxes, down payments, mileage penalties — which vary by contract and jurisdiction.
Results exclude tax, fees, down payments and end-of-lease charges. Provided for general information only and not financial advice.