Discount Calculator

A versatile and easy-to-use Node.js utility for calculating various types of discounts. Powered by DiscountCalculator, this package helps businesses and developers quickly implement discount calculations in their applications.

Features

• Multiple Discount Types:

  • Percentage discounts
  • Fixed amount discounts
  • "Buy X Get Y Free" promotions
  • Tiered discounts based on purchase thresholds

• Detailed Results:

  • Original amount
  • Discount amount
  • Final price
  • Savings percentage
  • Formatted output

• Easy Integration:

  • Simple API for developers
  • Command-line interface for quick calculations
  • Thoroughly documented with examples

Installation

npm install discount-calculator-js

Command Line Usage

After installing globally with npm install -g discount-calculator-js, you can use the calculator directly from your terminal:

discount-calculator

This will launch an interactive CLI that guides you through the discount calculation process.

API Usage

const { calculateDiscount } = require('discount-calculator-js');

// Example 1: Calculate a 20% discount on $100
const result1 = calculateDiscount(100, {
  type: 'percentage',
  value: 20,
  formatOutput: true
});
console.log(result1.formattedOutput);

// Example 2: Calculate a fixed $25 discount on $150
const result2 = calculateDiscount(150, {
  type: 'fixed',
  value: 25
});
console.log(`Final price: $${result2.finalPrice}`);

// Example 3: Calculate "Buy 2 Get 1 Free" for 5 items at $10 each
const result3 = calculateDiscount(10, {
  type: 'buyxgety',
  quantity: 5,
  buyQuantity: 2,
  getQuantity: 1
});
console.log(`You pay for ${result3.itemsPaid} items and get ${result3.itemsFree} free!`);

// Example 4: Tiered discount ($100+ = 10%, $200+ = 15%, $500+ = 20%)
const tiers = [
  { threshold: 100, discount: 10, type: 'percentage' },
  { threshold: 200, discount: 15, type: 'percentage' },
  { threshold: 500, discount: 20, type: 'percentage' }
];

const result4 = calculateDiscount(250, {
  type: 'tiered',
  tiers
});
console.log(`Discount applied: ${result4.discountValue}%`);

API Reference

calculateDiscount(amount, options)

Main function to calculate discounts based on the specified type.

Parameters:

• amount: (Number) The original price or item price
• options: (Object) Configuration options:
  • type: (String) Type of discount ('percentage', 'fixed', 'buyxgety', 'tiered')
  • value: (Number) The discount value (percentage or fixed amount)
  • formatOutput: (Boolean) Whether to include formatted output string
  • Additional parameters based on the discount type:
    • For 'buyxgety': quantity, buyQuantity, getQuantity
    • For 'tiered': tiers (Array of threshold objects)

Returns: An object containing:

• originalAmount: The starting amount
• discountType: The type of discount applied
• discountValue: The discount value
• discountAmount: The amount saved
• finalPrice: The price after discount
• savings: The amount saved
• savingsPercentage: The percentage saved
• formattedOutput: (if requested) String representation of the result

Additional Utility Functions

• calculatePercentageDiscount(amount, percentage)
• calculateFixedDiscount(amount, discountAmount)
• calculateBuyXGetYDiscount(amount, quantity, buyQuantity, getQuantity)
• calculateTieredDiscount(amount, tiers)
• formatResult(result)
• getAvailableDiscountTypes()

Examples

Percentage Discount

const result = calculatePercentageDiscount(100, 25);
// Result: 25% off $100 = $25 discount, final price $75

Fixed Discount

const result = calculateFixedDiscount(80, 15);
// Result: $15 off $80 = final price $65

Buy X Get Y Free

const result = calculateBuyXGetYDiscount(10, 8, 2, 1);
// For 8 items at $10 each with "Buy 2 Get 1 Free"
// Result: Pay for 6 items, get 2 free, total $60 instead of $80

Tiered Discount

const tiers = [
  { threshold: 50, discount: 5, type: 'percentage' },
  { threshold: 100, discount: 10, type: 'percentage' }
];
const result = calculateTieredDiscount(120, tiers);
// Result: 10% discount applied to $120

Use Cases

• E-commerce platforms
• Point of sale systems
• Pricing calculators
• Financial applications
• Budget planning tools

License

MIT

Try our advanced discount calculator.