Loan Calculator Using HTML,CSS and JavaScript With Source Code

Welcome to the Codewithrandom blog. In this blog, We learn how we create the Loan Calculator Using HTML, CSS, and JavaScript With Source Code. in this Loan Calculator we enter the Amount, Percentage and how many years it Show Total Payment, monthly payment, and total interest.

I hope you enjoy our blog so let's start with a basic HTML Structure for the Loan Calculator.

HTML and CSS Code For Loan Calculator

<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
<style>
#loading, #results{
display: none;
}
</style>
<title>Loan Calculator</title>
</head>
<body class="bg-dark">
<div class="container">
<div class="row">
<div class="col-md-6 mx-auro">
<div class="card card-body text-center mt-5">
<h1 class="heading display-5 pb-3">Loan Calculator</h1>
<form action="" id="loan-form">
<div class="form-group">
<div class="input-group">
<span class="input-group-text">$</span>
<input type="number" class="form-control" id="amount" placeholder="Loan Amout">
</div>
</div>
<div class="form-group">
<div class="input-group">
<span class="input-group-text">%</span>
<input type="number" class="form-control" id="interest" placeholder="Interest">
</div>
</div>
<div class="form-group">
<input type="number" class="form-control" id="years" placeholder="Years to repay">
</div>
<div class="form-group">
<input type="submit" value="Calculator" class="btn btn-dark btn-block">
</div>
</form>
<!-- Loader Here -->
<div id="loading">
<img src="img/loading.gif" alt="">
</div>
<!-- Results -->
<div id="results" class="pt-4">
<h5>Results</h5>
<div class="form-group">
<div class="input-group">
<span class="input-group-text">Total Payment</span>
<input type="number" class="form-control" id="total-payment" disabled>
</div>
</div>
<div class="form-group">
<div class="input-group">
<span class="input-group-text">Mothly Payment</span>
<input type="number" class="form-control" id="monthly-payment" disabled>
</div>
</div>
<div class="form-group">
<div class="input-group">
<span class="input-group-text">Total Interest</span>
<input type="number" class="form-control" id="total-interest" disabled>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<script src="app.js"></script>
</body>
</html>

There is all the Html code and Css code for the Loan Calculator. Now, you can see an output with Html and Css. then we write javascript for the add main functionality in Loan Calculator.

JavaScript Code For Loan Calculator

// //Listen for submit button
//document.getElementById('loan-form').addEventListener('submit',calculateResults);;
//Listen for submit button
const form = document.getElementById('loan-form');
//form.addEventListener('submit',calculateResults);//Without loader
form.addEventListener('submit',function(e){
//Hide Results
document.getElementById('results').style.display='none';
//Show Loader
document.getElementById('loading').style.display='block';
setTimeout(calculateResults,2000);
e.preventDefault();
});
//Calculate Results function
function calculateResults(e){
console.log('calculating...');
//UI cars
const ELamount = document.getElementById('amount');
const ELinterest = document.getElementById('interest');
const ELyears = document.getElementById('years');
const ELMonthly_payment = document.getElementById('monthly-payment');
const ELtotal_payment = document.getElementById('total-payment');
const ELtotal_interest = document.getElementById('total-interest');
const principal = parseFloat(ELamount.value);
const calculatedInterest = parseFloat(ELinterest.value) /100 /12;
const calculatedPayment = parseFloat(ELyears.value )*12;
//Create monthly payment
const x = Math.pow(1 + calculatedInterest, calculatedPayment);
const monthly = (principal * x * calculatedInterest) / (x - 1);
console.log(monthly);
if(isFinite(monthly)){//check whether it is finite or not
ELMonthly_payment.value = monthly.toFixed(2);
ELtotal_payment.value = (monthly*calculatedPayment).toFixed(2);
ELtotal_interest.value = ((monthly*calculatedPayment)-principal).toFixed(2);//fix to 2 deciman places
//Show Results
document.getElementById('results').style.display='block';
//Hide Loader
document.getElementById('loading').style.display='none';
}else{
console.log("Plase check your numbers");
//Display an error
showError('Plase check your number');
}
e.preventDefault();
}
function showError(error){
//Show Results
document.getElementById('results').style.display='none';
//Hide Loader
document.getElementById('loading').style.display='none';
//--------------------------------------------------------------------
//Create a div
const errorDiv = document.createElement('div');
//get elements
const ELcard = document.querySelector ('.card');
const ELheading = document.querySelector('.heading');
//Add class
errorDiv.className = 'alert alert-danger';
//create text node and append to dic
errorDiv.appendChild(document.createTextNode(error));
//Insert error above heading
ELcard.insertBefore(errorDiv, ELheading);
//clear error after 3 seconds
setTimeout(clearError, 3000);
}
function clearError(){
document.querySelector('.alert').remove();
}

Now we have completed our Loan Calculator. Here is our updated output with Html, Css, and JavaScript. Hope you like the Loan Calculator Project. you can see the output video and project screenshots. See our other blogs and gain knowledge in front-end development.

Thank you!

In this post, we learn how to create a Loan Calculator Using HTML, CSS, and JavaScript Source Code. If we made a mistake or any confusion, please drop a comment to reply or help you in easy learning.

Written by - Code With Random/Anki