GST India Price and Tax Calculator

An NPM package for calculating GST-inclusive and GST-exclusive prices in India based on MRP, sale price, base price, and tax percentage.

Features

• Calculate MRP, discount, sale price, base price, and detailed GST amounts.
• Lock calculations based on either SALEPRICE or BASEPRICE.
• Accurate currency conversions between subunits and standard units.
• Error handling for invalid inputs.

Installation

npm install @heartinz/gst-india-price-tax-calculator

Dependencies

Make sure to install the following dependencies as they are required for this package to function correctly:

npm install @heartinz/currency_subunit_converter
npm install @heartinz/gst_india_price_tax_calculator

Usage

import priceCalculator from '@heartinz/gst-india-price-tax-calculator';

const mrp = 1000;        // Maximum Retail Price in INR
const salePrice = 900;   // Sale Price in INR
const basePrice = 0;     // Base Price in INR (set to 0 if unknown)
const taxPercent = 18;   // GST percentage
const lock = 'SALEPRICE'; // Lock calculations based on 'SALEPRICE' or 'BASEPRICE'

try {
  const result = priceCalculator.calculateAllPrice(mrp, salePrice, basePrice, taxPercent, lock);
  console.log(result);
} catch (error) {
  console.error(error.message);
}

Function: calculateAllPrice

Parameters

• mrp (number): The Maximum Retail Price.
• salePrice (number): The Sale Price.
• basePrice (number): The Base Price (excluding GST).
• taxPercent (number): The GST percentage (must be a positive integer).
• lock (string): Determines which price to lock during calculation. Accepts 'SALEPRICE' or 'BASEPRICE'.

Returns

An object containing the calculated pricing details:

• mrp: Calculated MRP.
• discount: Calculated discount amount.
• salePrice: Calculated sale price.
• basePrice: Calculated base price (excluding GST).
• gstPercent: GST percentage used.
• gstAmount: Total GST amount.
• sgstPercent: SGST percentage.
• sgstAmount: SGST amount.
• cgstPercent: CGST percentage.
• cgstAmount: CGST amount.
• igstPercent: IGST percentage.
• igstAmount: IGST amount.

Exceptions

Throws an error if:

• mrp, salePrice, or basePrice are not valid decimal numbers.
• taxPercent is not a positive integer.
• lock is not 'SALEPRICE' or 'BASEPRICE'.

Example

import priceCalculator from '@heartinz/gst-india-price-tax-calculator';

const mrp = 1500;
const salePrice = 1350;
const basePrice = 0;
const taxPercent = 18;
const lock = 'SALEPRICE';

try {
  const result = priceCalculator.calculateAllPrice(mrp, salePrice, basePrice, taxPercent, lock);
  console.log(result);
} catch (error) {
  console.error(error.message);
}

Sample Output:

{
  "mrp": 1500,
  "discount": 150,
  "salePrice": 1350,
  "basePrice": 1144.07,
  "gstPercent": 18,
  "gstAmount": 205.93,
  "sgstPercent": 9,
  "sgstAmount": 102.96,
  "cgstPercent": 9,
  "cgstAmount": 102.96,
  "igstPercent": 0,
  "igstAmount": 0
}

Error Handling

The function includes input validation and will throw descriptive errors for invalid inputs:

• Invalid mrp: Must be a decimal number.
• Invalid salePrice: Must be a decimal number.
• Invalid basePrice: Must be a decimal number.
• Invalid taxPercent: Must be a positive integer.
• Invalid lock: Must be either 'SALEPRICE' or 'BASEPRICE'.

Contributing

Contributions are welcome! Please open an issue or submit a pull request for any bugs or improvements.

License

/**
 * Copyright (c) 2024 Kiran Morais
 * (Heartinz Technologies Private Limited, India)
 * All Rights Reserved. Unauthorized use, distribution, or modification of this code is prohibited.
 */

Note

This package relies on accurate currency conversions and GST calculations as per Indian taxation laws. Always ensure the tax percentages and calculations comply with the latest regulations.