THE NUMORIX GUIDE
How to use the Auto Lease Calculator
Last reviewed September 14, 2026
What this calculator does
The lease model sets adjusted capitalized cost to negotiated price minus down payment and depreciation amount to negotiated price minus residual value.
Formula and method
The lease model sets adjusted capitalized cost to negotiated price minus down payment and depreciation amount to negotiated price minus residual value. It converts the annual interest input to a money factor by dividing by 2,400, calculates finance charge as (adjusted cap cost + residual) x money factor, adds tax to depreciation per month plus finance charge, and totals payments plus down payment.
Variables and inputs
Enter MSRP, negotiated price, down payment, lease term in months, annual interest rate, residual value, and sales-tax rate. Dollar fields are dollars; term is months; rate and tax are percentages. MSRP is displayed but is not used by the engine after the negotiated price is entered.
Worked example
Using negotiated price $38,000, $2,000 down, residual $24,000, 36 months, 5% rate, and 7% tax, adjusted cap cost is $36,000. Depreciation is (38,000 - 24,000) / 36 = $388.89 per month. Money factor is 5 / 2,400 = 0.0020833, so finance charge is (36,000 + 24,000) x 0.0020833 = $125.00; tax is about 7% x (388.89 + 125) = $35.97, making payment about $549.86.
How to interpret the result
The payment reflects depreciation, finance charge, and tax under the route's lease convention. Residual value is the assumed vehicle value at lease end; a higher residual reduces modeled depreciation. Total lease cost includes the down payment, so a low payment with a large upfront amount may not be a low-cost offer.
Common mistakes to avoid
Do not enter a money factor in the interest-rate field; the engine converts an annual percentage by dividing by 2,400. Distinguish MSRP from negotiated price and residual dollars. Compare acquisition, disposition, mileage, and wear charges separately.
Assumptions and limitations
MSRP and the depreciation input in the type are not used by the calculation; depreciation is derived from negotiated price and residual. The model excludes acquisition fees, registration, cap-cost reductions other than down payment, mileage charges, disposition fees, and jurisdiction-specific tax treatment.