Auto Loan Payment Fixed Rate Estimator
This estimator computes periodic payments, the financed amount, total amount paid, and total interest for a fixed‑rate auto loan. It includes common adjustments: down payment, trade‑in value, fees, and sales tax applied to the taxable vehicle amount.
The tool assumes a fixed nominal annual interest rate and level (equal) payments per period. Select the payments per year to model monthly, biweekly, weekly, or annual schedules.
Inputs
Results
Financed amount
$29,660.00
Periodic payment
$559.72
Total of all payments
$33,583.25
Total interest paid
$3,923.25
| Output | Value | Unit |
|---|---|---|
| Financed amount | $29,660.00 | — |
| Periodic payment | $559.72 | — |
| Total of all payments | $33,583.25 | — |
| Total interest paid | $3,923.25 | — |
Visualization
Methodology
We use the standard amortizing fixed‑rate loan formula: payment = r * PV / (1 - (1+r)^-n), where r is the periodic interest rate and n is the total number of payments. The financed amount (PV) is the vehicle price less down payment and trade‑in, plus fees and sales tax (applied to the taxable vehicle amount).
All numeric calculations use IEEE‑754-compatible arithmetic conventions where implemented; results are rounded for display to two decimal places. This estimator is intended for planning and comparison; final loan offers depend on lender underwriting and local tax rules.
Worked examples
Example: $30,000 vehicle, $3,000 down, $0 trade‑in, 8% sales tax, $500 fees, 5% APR, 5 years, monthly payments → financed ≈ $28,540; monthly payment ≈ $539. Total interest ≈ $3,375. (Values are illustrative.)
Further resources
Expert Q&A
How is sales tax applied?
Sales tax is applied to the taxable base defined here as vehicle price minus down payment and trade‑in. Local tax rules vary; some jurisdictions tax the full price or apply exemptions. Confirm with your dealer or local tax authority.
What happens if the interest rate is zero?
For a 0% nominal rate, the periodic payment simplifies to financed amount divided by total number of payments. Some implementations may show division by zero in the raw formula; this estimator treats 0% as the simple evenly divided case for practical use.
Are results guaranteed to match a lender's offer?
No. This estimator provides an approximation for planning. Actual loan offers depend on credit underwriting, fees, insurance requirements, and lender amortization conventions.
How precise are the results?
Displayed results are rounded to two decimal places. Under the hood calculations follow common floating point conventions; small rounding differences may appear versus lender statements.
Is personal data collected by this tool?
This configuration describes calculation logic only. Implementations should follow organizational privacy policies and applicable regulations when collecting or storing user inputs.
Sources & citations
- National Institute of Standards and Technology (NIST) — https://www.nist.gov
- International Organization for Standardization (ISO) — https://www.iso.org
- IEEE Standards Association — https://standards.ieee.org
- Occupational Safety and Health Administration (OSHA) — https://www.osha.gov