Enter loan details and click "Calculate" to see the amortization schedule.
Understanding Loan Payments and Amortization
A loan calculator with an amortization table is an essential tool for anyone taking out a loan, whether it's a mortgage, car loan, personal loan, or business financing. It helps you understand the cost of borrowing, how your payments are structured, and how your loan balance decreases over time.
How Loan Payments Are Calculated
The monthly payment for an amortizing loan is calculated using the following formula:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
Where:
M = Your total monthly mortgage payment
P = The principal loan amount (the amount you borrow)
i = Your monthly interest rate (annual rate divided by 12)
n = The total number of payments over the loan's lifetime (loan term in years multiplied by 12)
This formula ensures that each payment is the same amount throughout the loan term. In the early stages of the loan, a larger portion of your payment goes towards interest, while a smaller portion reduces the principal. As time goes on, this ratio shifts, with more of your payment going towards the principal.
What is an Amortization Table?
An amortization table, also known as a loan amortization schedule, breaks down each monthly payment into its principal and interest components. It shows:
The payment number (e.g., Payment 1, Payment 2)
The date of the payment
The amount of the payment
How much of the payment goes towards interest
How much of the payment goes towards the principal
The remaining loan balance after the payment is made
By reviewing the amortization table, you can visualize how your debt is being paid down and how the interest charges accumulate. It can also help you see the long-term cost of the loan and how much interest you'll pay over the entire term.
Why Use a Loan Calculator?
Budgeting: Accurately determine your monthly loan obligations to manage your budget effectively.
Comparison Shopping: Compare loan offers from different lenders by inputting their terms to see which offers the best overall cost.
Financial Planning: Understand the impact of different loan terms (e.g., shorter vs. longer terms) on your total payments and interest costs.
Early Payoff Strategy: See how extra payments might reduce the loan term and total interest paid.
Transparency: Gain a clear understanding of how loans work and avoid hidden costs.
Using this calculator provides a clear, transparent view of your loan's financial journey, empowering you to make informed decisions.
function calculateLoan() {
var loanAmount = parseFloat(document.getElementById("loanAmount").value);
var annualInterestRate = parseFloat(document.getElementById("annualInterestRate").value);
var loanTermYears = parseInt(document.getElementById("loanTermYears").value);
var tableContainer = document.getElementById("table-container");
tableContainer.innerHTML = "; // Clear previous table
if (isNaN(loanAmount) || isNaN(annualInterestRate) || isNaN(loanTermYears) ||
loanAmount <= 0 || annualInterestRate < 0 || loanTermYears <= 0) {
tableContainer.innerHTML = 'Please enter valid positive numbers for all fields.';
document.getElementById("monthlyPayment").textContent = "-";
document.getElementById("totalPrincipalPaid").textContent = "-";
document.getElementById("totalInterest").textContent = "-";
document.getElementById("totalPayment").textContent = "-";
return;
}
var monthlyInterestRate = annualInterestRate / 100 / 12;
var numberOfPayments = loanTermYears * 12;
var totalInterest = 0;
var totalPrincipalPaid = 0;
var totalPayment = 0;
var monthlyPayment = 0;
if (monthlyInterestRate === 0) {
monthlyPayment = loanAmount / numberOfPayments;
} else {
monthlyPayment = loanAmount * (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
}
monthlyPayment = Math.round(monthlyPayment * 100) / 100;
totalPayment = monthlyPayment * numberOfPayments;
totalInterest = totalPayment – loanAmount;
totalPrincipalPaid = loanAmount; // In a full amortization, this will be the original loan amount
document.getElementById("monthlyPayment").textContent = "$" + monthlyPayment.toFixed(2);
document.getElementById("totalPrincipalPaid").textContent = "$" + loanAmount.toFixed(2);
document.getElementById("totalInterest").textContent = "$" + totalInterest.toFixed(2);
document.getElementById("totalPayment").textContent = "$" + totalPayment.toFixed(2);
// Build Amortization Table
var tableHTML = "
Payment #
Date
Payment
Principal
Interest
Balance
";
var remainingBalance = loanAmount;
var currentDate = new Date(); // Starting date for calculations
for (var i = 1; i <= numberOfPayments; i++) {
var interestForPayment = remainingBalance * monthlyInterestRate;
var principalForPayment = monthlyPayment – interestForPayment;
// Adjust for the last payment to ensure balance is exactly zero
if (i === numberOfPayments) {
principalForPayment = remainingBalance;
monthlyPayment = principalForPayment + interestForPayment; // Adjust final payment amount
}
remainingBalance -= principalForPayment;
// Ensure balance doesn't go below zero due to rounding
if (remainingBalance < 0) remainingBalance = 0;
var paymentDate = new Date(currentDate.getFullYear(), currentDate.getMonth() + i, currentDate.getDate());
var formattedDate = (paymentDate.getMonth() + 1) + "/" + paymentDate.getDate() + "/" + paymentDate.getFullYear();
tableHTML += "