Calculate CGPA using Python Django

Last Updated : 24 May, 2025

We will build a secure and user-friendly CGPA calculator using Django. Starting with user registration and login, the app lets students input their subjects, grades, and credits. After entering all data, they can instantly calculate their CGPA and generate a printable result.

What is CGPA Calculator ?

A CGPA (Cumulative Grade Point Average) calculator is a tool used to determine a student's overall academic performance based on the grades obtained in various courses or subjects over a specific period. It assigns a numerical value, known as the Grade Point, to each grade received, and the CGPA is calculated as the average of these grade points.

Project Setup

Create Project and App

Start by creating a new Django project and app:

django-admin startproject core
cd core
python manage.py startapp home

Register the App

Add the app to your settings.py under INSTALLED_APPS:

INSTALLED_APPS = [
"django.contrib.admin",
"django.contrib.auth",
"django.contrib.contenttypes",
"django.contrib.sessions",
"django.contrib.messages",
"django.contrib.staticfiles",
"home",
]

File Structure:

👁 file

Define Models (models.py)

models.py : This Django model, named "Subject," includes fields for user (linked to the built-in User model), subject name, grade (with predefined choices), and credit. The `__str__` method customizes the string representation of an instance.

Handle Business Logic in Views

views.py : In below code, Django application includes views for a CGPA calculator, subject editing, subject deletion, and a result view. It also has user authentication functionalities, including a login page, registration page, and a logout function. The CGPA calculator computes the CGPA based on subjects and their grades, while the result view displays the result in a PDF template. User authentication is implemented with login, registration, and logout functionalities. Error messages are displayed for incorrect login attempts or registration issues.

Create Subject Form

forms.py : The "SubjectForm" in Django is a ModelForm linked to the "Subject" model. It includes fields for subject name, credit, and grade, enabling easy creation and modification of Subject instances through user interfaces.

Configure URLs

Project urls.py

The main `urls.py` file in this Django project includes paths for the admin interface and includes URLs from the 'home.urls' module using the 'include' function, promoting modularity and organization in the project's URL configuration.

App urls.py

The 'urls.py' file in the 'home' app of this Django project includes paths for views like 'cgpa_calculator', 'edit_subject', 'delete_subject', 'result', 'login_page', 'custom_logout', and 'register_page'. These paths correspond to various functionalities, defining the URL patterns for navigation within the application.

Creating GUI

login.html: This HTML file implements a simple login form for a CGPA Calculator web application using Bootstrap. It includes fields for username and password, with messages displayed for login outcomes. The form is styled using Bootstrap classes for a clean and responsive design, and there's a link to the registration page.

register.html: This HTML file implements a registration form for a CGPA Calculator web application using Bootstrap. It includes fields for username and password, with messages displayed for registration outcomes. The form is styled using Bootstrap classes for a clean and responsive design, and there's a link to the login page for existing users. The "Register" button has a style attribute for additional customization.

index.html: This HTML file provides a clean and user-friendly web interface for a CGPA Calculator. It includes a form to add subjects, a table to display existing subjects with their grades and credits, and buttons for editing or deleting subjects. The styling is done using a combination of inline styles and embedded CSS. Additionally, there's a logout button at the bottom for user convenience.

edit_subject.html: This HTML file offers a compact and centered layout for editing a subject. It includes a form with input fields, a "Save Changes" button linked to the 'edit_subject' view, and a "Cancel" button redirecting to the 'cgpa_calculator' view. Styling is kept minimal for a clean and focused editing experience.

pdf.html: This HTML file represents a CGPA Calculator result page with a table displaying subjects, grades, and credits. It calculates and displays the CGPA. The "Generate Receipt" button triggers a JavaScript function to copy the content of the 'calculator' div, open a new window, and print the receipt. The styling is clean, and the jsPDF library is included for potential PDF generation, although not currently used in the provided code.