The buy scenario compares your down payment and payments made over the lease horizon with the equity left after subtracting the remaining loan balance from the car’s estimated value.
It does not include fuel, maintenance, insurance, mileage charges, wear-and-tear penalties, or tax differences unless you model those separately.
Lease vs buy car guide: comparing lease cost, loan balance, and equity at the same horizon
A lease vs buy car calculator is most useful when it compares both options over the same ownership horizon instead of just comparing a lease payment with a loan payment. This page shows the total lease outlay, the buy-side payments made over the lease period, the remaining loan balance at that same point, and the equity left in the vehicle so you can see which path is cheaper on the assumptions entered.
What this lease-versus-buy comparison is actually measuring
A lease payment and a loan payment are not directly equivalent because they buy different things. Leasing usually pays for depreciation during a fixed term plus the lessor's rent charge, then returns the vehicle unless you exercise a purchase option. Buying uses a loan that gradually creates ownership equity, which means the right comparison is not just monthly payment but total cash paid and what asset value remains at the end of the same time window.
This calculator treats the lease term as the shared horizon. On the lease side, that means down payment plus monthly lease payments. On the buy side, it means the buy down payment plus all loan payments made during the same number of months, then offset by the buyer's equity at that point. Equity is the vehicle's estimated value minus the remaining loan balance, which is why the buy option can still be competitive even when the monthly loan payment is higher than the lease payment.
The buy comparison uses standard amortisation math for the loan payment, then projects the remaining balance after the same number of months as the lease term. That remaining balance matters because a borrower who sells or trades the car after three years may still owe part of a five-year or six-year loan. Ignoring that balance can make buying look artificially cheap or expensive depending on the residual-value assumption.
The comparison therefore separates four buy-side pieces: the monthly loan payment, the total payments made during the lease horizon, the remaining loan balance at that point, and the resulting equity after subtracting the remaining balance from the estimated vehicle value. Once you have those, the net buy cost over the shared horizon becomes much clearer.
Loan payment = P × r / (1 − (1 + r)^(-n))
This is the standard fixed-rate amortisation formula for the buy monthly payment, where P is the amount financed, r is the monthly interest rate, and n is the number of monthly payments.
Equity at lease end = estimated car value at horizon − remaining loan balance at horizon
Positive equity reduces the effective buy cost because the buyer still owns value after the shared comparison period.
Net buy cost over lease horizon = buy down payment + buy payments made during horizon − equity at horizon
This expresses the buy path over the same period as the lease by offsetting cash paid with the value still left in the vehicle.
Suppose a car costs $35,000. The lease requires $2,000 down and $400 per month for 36 months, so the lease outlay is $16,400 over the comparison period. Now assume the buy option uses a $5,000 down payment and finances the rest over 60 months at 5%. The loan payment is higher than the lease payment, but the buyer is also building equity with each payment.
After 36 months, the buyer has made 36 loan payments, still has a remaining loan balance, and owns a car that may still be worth around $22,000. If the estimated value exceeds the remaining balance, that positive equity lowers the net cost of buying over the same 36-month window. If depreciation is worse than expected and the loan balance stays above the value, the buy option can look much less attractive because negative equity increases the effective cost.
This is the core reason a lease versus buy car calculator should not stop at 'monthly payment versus monthly payment.' The right decision depends on total lease cash outlay, financed-balance paydown, remaining balance, and how realistic the future vehicle value is.
What this comparison does not include
This page keeps the comparison focused on finance structure. It does not include fuel, maintenance, insurance, lease acquisition fees, registration, taxes, mileage overage charges, wear-and-tear penalties, disposition fees, or the opportunity cost of tying up a larger buy-side down payment. Those items can change the answer materially, especially when a lease has strict mileage limits or the buy loan includes dealer add-ons.
It also treats the future car value as an entered estimate rather than a guaranteed market outcome. If resale demand weakens, equity can disappear faster than expected. If the vehicle holds value unusually well, buying can become more attractive than a payment-only comparison would suggest. Use the result as a planning comparison, then test it again with conservative and optimistic value assumptions before making a real vehicle decision.
Why is comparing monthly payment alone misleading?
A lease payment usually covers depreciation plus the lessor's rent charge, while a loan payment gradually builds ownership equity. Two options can have similar monthly payments but very different outcomes after three years because the buyer may still own positive equity in the car while the lessee returns the vehicle with no asset left. That is why this page compares total cash paid and remaining equity at the same horizon instead of stopping at the payment headline.
Why does the buy option need a remaining loan balance?
Because the comparison horizon is often shorter than the loan term. If the lease lasts 36 months but the loan lasts 60 months, the buyer still owes part of the loan when the lease would normally end. Ignoring that balance would overstate the benefit of buying. The remaining balance is necessary to work out how much equity is really left if the car were sold or traded at the lease horizon.
What does equity at lease end mean in this comparison?
It is the car's estimated market value at the comparison horizon minus the remaining loan balance at that same point. Positive equity means the vehicle is worth more than the debt still owed, which lowers the effective cost of buying. Negative equity means the vehicle is worth less than the remaining balance, which raises the effective cost because extra debt would still need to be cleared.
Can leasing still be the better option even if buying creates equity?
Yes. Leasing can still win if the lease payment is much lower, the buy loan is expensive, the vehicle is expected to depreciate quickly, or the driver values the flexibility of handing the car back before major maintenance risk starts. The point of the comparison is not to assume buying always wins on equity, but to show whether the equity left after the same period is enough to justify the higher buy-side cash outlay.
