Calculate your monthly payments and total interest costs instantly.
Years
Months
Monthly Payment:$0.00
Total Principal Paid:$0.00
Total Interest Paid:$0.00
Total Cost of Loan:$0.00
Understanding Personal Loan Repayment
When you take out a personal loan, understanding the long-term financial commitment is crucial. A personal loan is typically an unsecured debt that is repaid in fixed monthly installments over a set period. Use this calculator to see how different interest rates and loan terms affect your monthly budget and the total amount you will pay back to the lender.
How Repayment is Calculated
The calculation for a personal loan follows an amortization formula. Your monthly payment remains constant, but the portion of the payment going toward the principal versus interest changes over time. In the beginning, a larger share of your payment goes toward interest. As the balance decreases, more of your payment goes toward the principal.
Key Factors Influencing Your Loan Cost
Principal Amount: The total amount of money you borrow.
Annual Percentage Rate (APR): This includes the interest rate plus any fees charged by the lender. A higher APR means higher monthly payments.
Loan Term: The length of time you have to repay the loan. Longer terms result in lower monthly payments but significantly higher total interest costs over the life of the loan.
Example Comparison
Imagine you borrow $15,000 at a 10% interest rate:
3-Year Term (36 Months): Monthly payment is approximately $484.01. Total interest paid is $2,424.36.
5-Year Term (60 Months): Monthly payment drops to $318.71. However, the total interest paid jumps to $4,122.60.
As seen in the example, extending your loan term by just two years can nearly double the interest you pay, even though it makes the monthly bill more manageable.
Tips for Lowering Loan Costs
If you find that the total cost of the loan is too high, consider improving your credit score before applying to secure a lower interest rate. Alternatively, choose the shortest repayment term you can comfortably afford to minimize the interest accumulation.
function calculateLoan() {
var principal = parseFloat(document.getElementById("loanAmount").value);
var annualRate = parseFloat(document.getElementById("interestRate").value);
var term = parseFloat(document.getElementById("loanTerm").value);
var termType = document.getElementById("termType").value;
var resultsArea = document.getElementById("resultsArea");
// Validation
if (isNaN(principal) || principal <= 0 || isNaN(annualRate) || annualRate < 0 || isNaN(term) || term <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
// Convert term to months
var numberOfMonths = (termType === "years") ? term * 12 : term;
// Monthly interest rate
var monthlyRate = (annualRate / 100) / 12;
var monthlyPayment;
// Handle 0% interest edge case
if (monthlyRate === 0) {
monthlyPayment = principal / numberOfMonths;
} else {
// Amortization Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var x = Math.pow(1 + monthlyRate, numberOfMonths);
monthlyPayment = (principal * x * monthlyRate) / (x – 1);
}
var totalPayment = monthlyPayment * numberOfMonths;
var totalInterest = totalPayment – principal;
// Display Results
document.getElementById("monthlyPaymentDisplay").innerText = "$" + monthlyPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalPrincipalDisplay").innerText = "$" + principal.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalInterestDisplay").innerText = "$" + totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalCostDisplay").innerText = "$" + totalPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
resultsArea.style.display = "block";
// Scroll to results on mobile
if (window.innerWidth < 600) {
resultsArea.scrollIntoView({ behavior: 'smooth' });
}
}