Mortgage Calculator using React

Last Updated : 23 Jul, 2025

In this article, we will create a Mortgage Calculator using React, allowing users to estimate their monthly mortgage payments based on the loan amount, annual rate of interest, and loan term in years. The application provides instant feedback, displaying the calculated monthly payment, total payable amount, and total interest.
The application uses React's useState hook to manage state variables for the principal amount, annual interest rate, loan term, monthly payment, total payable amount, total interest, and error handling. Users are prompted to input the necessary information, with real-time validation to ensure accurate calculations.

Preview:

👁 Screenshot-(188)

Pre-requisites:

Project Structure:

👁 Screenshot-(129)

Steps to Create the Project:

Step 1: Set up React project using the command

npm create vite@latest <<name_of_project>> --template react

Step 2: Navigate to the project folder using

cd <<Name_of_project>>

Step 3: Install necessary dependencies

npm install

Step 4: Create MortgageCalculator.js component along with its CSS file.

Approach

First use React's 'useState' hook for managing component state, handling variables like loan amount, interest rate, and error messages.
The `calculateMonthlyPayment` function solves mortgage details based on user input, ensuring valid values before performing calculations.
Features input fields for loan details and a button triggering the calculation, with results displayed if the input is valid.
Connects input fields to state variables using `value` and `onChange`, ensuring real-time updates, and triggers calculations on the "Calculate" button click.
App component includes MortgageCalculator, rendering a simple layout with a header and the mortgage calculator below, with imported CSS for styling.

Example: In this example we will see the implementation of above approach. add the below code in respective files.