Grade Calculator
Grade Calculator
1. Overview
This web application calculates academic grades based on marks obtained in multiple subjects. It combines HTML for structure, CSS for styling, and JavaScript for functionality to create an interactive grade calculation tool.
2. Key Features
- 7-subject input system
- Real-time grade calculation
- Input validation
- Total marks display
- Average percentage calculation
- Visual grade display
- Responsive design
- Error handling
3. HTML Structure
The HTML document contains:
- Input fields for 7 subjects (Mathematics, Physics, Chemistry, Biology, English, History, Computer Science)
- Calculate button
- Result display section
- Semantic HTML5 elements
- Input validation attributes (min/max values)
4. CSS Styling
The styling includes:
- Centered layout with flexbox
- Clean material design-inspired interface
- Responsive container
- Input field styling
- Button hover effects
- Visual hierarchy with typography
- Color-coded results
- Box shadows and border radius for depth
- Mobile-friendly design
5. JavaScript Functionality
The script handles:
- Input validation (numeric checks, range verification)
- Mathematical calculations:javascriptCopyconst total = maths + physics + chemistry + biology + english + history + computer; const average = total / 7;
- Grade determination logic:javascriptCopyif (average >= 90) grade = ‘A+’; else if (average >= 80) grade = ‘A’; …
- Dynamic DOM manipulation for results display
- Error handling for invalid inputs
6. How It Works
- User inputs marks (0-100) for all subjects
- Clicking “Calculate Grade” triggers the function
- System validates all inputs
- Calculates total and average
- Determines grade based on average
- Displays results with formatting
7. Grading System
| Average Percentage | Grade |
|---|---|
| 90% and above | A+ |
| 80-89% | A |
| 70-79% | B |
| 60-69% | C |
| 50-59% | D |
| Below 50% | F |
8. Input Validation
- Ensures all fields contain numbers
- Verifies marks are between 0-100
- Shows alert for invalid/missing inputs
- Prevents calculation with empty fields
9. Responsive Design
- Works on all screen sizes
- Proper spacing and padding
- Readable typography
- Touch-friendly inputs
- Adaptive container width
10. Customization Options
Developers can modify:
- Number of subjects
- Subject names
- Grading scale
- Color scheme
- Styling properties
- Calculation formula
- Result display format
11. How to Use
- Enter marks in all subject fields
- Click “Calculate Grade”
- View results:
- Total aggregated marks
- Average percentage
- Final letter grade
12. Error Handling
- Checks for NaN (Not-a-Number) values
- Validates number ranges
- Provides clear error messages
- Prevents invalid submissions
- Maintains data integrity
13. Technical Specifications
- Frontend only (no backend)
- Vanilla JavaScript (no dependencies)
- CSS3 features
- HTML5 form validation
- Client-side processing
- Cross-browser compatible
14. Possible Modifications
- Add weightage to different subjects
- Include grade point average (GPA)
- Implement subject-wise grading
- Add data persistence
- Create printable reports
- Add dark mode toggle
This documentation provides comprehensive information about the application’s structure, functionality, and customization potential. The code demonstrates fundamental web development concepts while maintaining practical utility for educational purposes.maintaining practical utility for educational purposes.
