Car Loan Calculator With Extra Payments

Instantly see how additional payments reduce your interest and shorten your payoff time.

Enter your loan details to begin.

Calculation Methodology

This section explains how the calculator processes your loan data.

Monthly Payment Formula

Your monthly payment is determined using the standard amortization formula:

M = P × [r(1 + r)^n] / [(1 + r)^n − 1]

Where:
• M = Monthly payment
• P = Loan principal
• r = Monthly interest rate (annual rate ÷ 12)
• n = Number of total payments (loan term in years × 12)

Interest & Principal Breakdown

Each payment is divided as follows:

Interest = Remaining Balance × Monthly Interest Rate
Principal = Monthly Payment − Interest
New Balance = Previous Balance − Principal

How Extra Payments Help

Any extra amount is applied straight to the principal, which:
• Lowers your balance more quickly
• Reduces total interest paid
• Shortens the loan length
• Can save considerable money over time

Payment Frequency Options

To compare different schedules, all frequencies are converted to monthly equivalents:
• Monthly = 1 payment per month
• Bi-weekly ≈ 2.17 payments monthly (26 ÷ 12)
• Annual = 1 payment every year

References

Based on:
• Standard amortization concepts
• CFPB loan guidance
• Federal Reserve interest rate standards

Note: Results are estimates. Real payments may differ depending on lender rules and timing.