Auto Loan Calculator

Planning to buy a new or used vehicle? Use our Auto Loan Calculator to estimate your monthly payments and see how different factors like trade-ins, down payments, and sales tax affect your final cost.

Understanding Car Financing

When you take out a car loan, you borrow a specific amount of money and agree to pay it back over a set period, known as the loan term. In addition to the principal (the amount borrowed), you also pay interest to the lender.

The Monthly Payment Formula

The standard formula for calculating a fixed monthly car payment ($M$) is:

$M = P \frac{r(1+r)^n}{(1+r)^n - 1}$

Where:

• $P$ = Principal (Total Loan Amount).
• $r$ = Monthly interest rate (Annual Rate / 12).
• $n$ = Total number of monthly payments.

Calculating the Total Cost

It's important to look beyond the monthly payment. The total cost of the loan is the sum of all payments over the life of the loan:

$C = M \times n$

The total interest paid is the difference between this cost and the principal:

$I = C - P$

Frequently Asked Questions

How does a down payment affect my monthly car payment?

A larger down payment reduces the principal amount you need to borrow. This directly lowers your monthly payment and significantly reduces the total interest you will pay over the life of the loan.

Should I choose a longer or shorter loan term?

A longer loan term (e.g., 72 months) will give you a lower monthly payment, but you will pay much more in interest over time. A shorter term (e.g., 36 or 48 months) saves you money on interest but requires a higher monthly commitment.

How does trade-in value work with sales tax?

In many jurisdictions, the value of your trade-in is subtracted from the vehicle's price before sales tax is applied. This "tax credit" can save you hundreds of dollars on top of the trade-in value itself.