Estimate your monthly payments and total interest costs instantly.
Monthly Payment:$0.00
Total Principal:$0.00
Total Interest Paid:$0.00
Upfront Fee Paid:$0.00
Total Cost of Loan:$0.00
Understanding Your Personal Loan Calculation
A personal loan is an unsecured or secured debt that is typically repaid in fixed monthly installments over a set period. Whether you are consolidating debt, funding a home improvement project, or covering an emergency expense, understanding the math behind your loan is crucial for financial health.
How the Monthly Payment is Calculated
The calculator uses the standard amortization formula to determine your fixed monthly payment:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
M: Total monthly payment
P: Principal loan amount
i: Monthly interest rate (annual rate divided by 12)
n: Number of months (years multiplied by 12)
Realistic Example:
If you borrow $15,000 at an 8% interest rate for a 3-year term:
Your monthly payment would be: $470.05
Total interest paid over 3 years: $1,921.65
Total repayment amount: $16,921.65
Factors That Affect Your Loan Cost
Three primary factors dictate how much you will ultimately pay back to the lender:
Credit Score: Lenders use your credit score to determine the interest rate. A higher score typically unlocks lower rates, significantly reducing the total interest paid.
Loan Term: Short-term loans (2-3 years) have higher monthly payments but lower total interest. Long-term loans (5-7 years) have lower monthly payments but cost much more in interest over time.
Fees: Many personal loans include an "origination fee" (usually 1% to 8%). This is often deducted from the loan proceeds or added to the balance, increasing your effective APR.
Tips for Getting the Best Rate
Before signing a loan agreement, consider pre-qualifying with multiple lenders to compare APRs. Look out for "prepayment penalties"—fees charged if you pay the loan off early. Opting for a lender with no prepayment penalties allows you to save on interest if you come into extra cash later.
function calculatePersonalLoan() {
var amount = parseFloat(document.getElementById('loanAmount').value);
var annualRate = parseFloat(document.getElementById('interestRate').value);
var years = parseFloat(document.getElementById('loanTerm').value);
var feePercent = parseFloat(document.getElementById('originationFee').value);
if (isNaN(amount) || isNaN(annualRate) || isNaN(years) || amount <= 0 || annualRate < 0 || years <= 0) {
alert("Please enter valid positive numbers for all required fields.");
return;
}
// Calculations
var monthlyRate = (annualRate / 100) / 12;
var numberOfPayments = years * 12;
var monthlyPayment = 0;
if (monthlyRate === 0) {
monthlyPayment = amount / numberOfPayments;
} else {
monthlyPayment = amount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var totalRepayment = monthlyPayment * numberOfPayments;
var totalInterest = totalRepayment – amount;
var originationFeeValue = (feePercent / 100) * amount;
var totalCost = totalRepayment + originationFeeValue;
// Display Results
document.getElementById('resMonthly').innerText = '$' + monthlyPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resPrincipal').innerText = '$' + amount.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resInterest').innerText = '$' + totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resFee').innerText = '$' + originationFeeValue.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resTotal').innerText = '$' + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('loanResults').style.display = 'block';
}