Universal Tax Calculator

A comprehensive tax calculator supporting multiple countries' tax systems. Built with TypeScript and designed for accuracy and ease of use.

Features

• Support for 20+ countries' tax systems
• Accurate tax bracket calculations
• Social security tax calculations
• Currency formatting by locale
• Standard deduction support
• Comprehensive error handling

Installation

npm install universal-tax-calculator

Usage

import TaxCalculator from 'universal-tax-calculator';

// Create a calculator instance for a specific country
const calculator = new TaxCalculator('US');

// Calculate taxes for a given income
const result = calculator.calculateTax(100000);

console.log(result);
// Output:
// {
//   grossIncome: 100000,
//   taxableIncome: 86150,
//   totalTax: 15213.50,
//   effectiveRate: 0.1766,
//   marginalRate: 0.24,
//   socialSecurityTax: 6200,
//   netIncome: 78586.50,
//   breakdown: [...]
// }

// Format currency
const formatted = calculator.formatCurrency(result.netIncome);
console.log(formatted); // "$78,586.50"

Supported Countries

• North America: US, Canada, Mexico
• Europe: UK, Germany, France, Italy, Spain
• Asia: Japan, China, India, Singapore
• Oceania: Australia, New Zealand
• South America: Brazil, Argentina
• Africa: South Africa, Nigeria
• Middle East: UAE, Saudi Arabia, Israel

API Reference

TaxCalculator

Constructor

constructor(country: string)

Methods

calculateTax

calculateTax(grossIncome: number, options?: {
  additionalDeductions?: number;
  includeSocialSecurity?: boolean;
}): TaxResult

formatCurrency

formatCurrency(amount: number): string

getDeductions

getDeductions(): { [key: string]: number }

getTaxBrackets

getTaxBrackets(): TaxBracket[]

Development

# Install dependencies
npm install

# Run tests
npm test

# Build
npm run build

# Lint
npm run lint

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.