Amortization Calculator for 100 000 at 3 for 15 Years

This amortization calculator helps you determine your monthly loan payments, total interest paid, and complete payment schedule for a $100,000 loan at 3% annual interest over 15 years. The calculator uses standard amortization formulas to provide accurate results based on your input parameters.

How to Use This Calculator

Using this amortization calculator is simple:

Enter the loan amount in the "Loan Amount" field (default is $100,000)
Enter the annual interest rate in the "Annual Interest Rate" field (default is 3%)
Select the loan term in years from the dropdown menu (default is 15 years)
Click the "Calculate" button to see your results
Review the monthly payment, total interest, and complete payment schedule

The calculator will display your monthly payment amount, total interest paid over the life of the loan, and a complete amortization schedule showing each payment's principal and interest components.

How Loan Amortization Works

Amortization is the process of paying off a loan in regular installments over time. Each payment consists of both principal (the original amount borrowed) and interest (the cost of borrowing).

Amortization Formula

The monthly payment (PMT) is calculated using the formula:

PMT = P × [r(1 + r)ⁿ] / [(1 + r)ⁿ - 1]

Where:

P = principal loan amount
r = monthly interest rate (annual rate divided by 12)
n = number of payments (loan term in years × 12)

For example, with a $100,000 loan at 3% annual interest over 15 years:

Monthly interest rate = 3% ÷ 12 = 0.25% or 0.0025
Number of payments = 15 × 12 = 180
Monthly payment = $100,000 × [0.0025(1 + 0.0025)¹⁸⁰] / [(1 + 0.0025)¹⁸⁰ - 1] ≈ $743.65

Over the 15-year term, you would make 180 payments totaling approximately $133,867, with $33,867 going toward interest.

Worked Example

Let's calculate the amortization for a $100,000 loan at 3% annual interest over 15 years:

Payment #	Payment Amount	Principal	Interest	Remaining Balance
1	$743.65	$256.35	$487.30	$99,743.65
2	$743.65	$258.09	$485.56	$99,485.56
3	$743.65	$259.84	$483.81	$99,225.72
...	...	...	...	...
180	$743.65	$743.65	$0.00	$0.00

As you can see, the interest portion decreases over time while the principal portion increases. This is because you're paying down more of the principal each month as the loan balance decreases.

Note: The first few payments will have a higher interest component since you're paying interest on the full loan amount. As the loan balance decreases, the interest portion of each payment will decrease while the principal portion increases.

Frequently Asked Questions

What is amortization?

Amortization is the process of paying off a loan in regular installments over time. Each payment consists of both principal (the original amount borrowed) and interest (the cost of borrowing).

How is the monthly payment calculated?

The monthly payment is calculated using the standard amortization formula that takes into account the loan amount, annual interest rate, and loan term. The formula ensures that the loan is fully paid off at the end of the term.

What happens if I make extra payments?

Making extra payments can significantly reduce the total interest paid and shorten the loan term. Each extra payment will first go toward the interest, reducing the remaining balance faster and saving on interest costs.

Is the interest rate fixed or variable?

The calculator assumes a fixed interest rate. If your loan has a variable rate, the payments would change over time based on market conditions.