gst_calculator 0.0.3

Indian GST calculator for Dart and Flutter. Add or remove GST, split CGST/SGST/IGST, with optional paise-accurate rounding.

example/main.dart

import 'package:gst_calculator/gst_calculator.dart';

void main() {
  // GST-exclusive price: add 18% GST to ₹1,000 for a sale within one state.
  final added = GstCalculator.addGST(amount: 1000, gstRate: 18);
  print('Base:  ${added.baseAmount}'); // 1000.0
  print('CGST:  ${added.cgst}'); // 90.0
  print('SGST:  ${added.sgst}'); // 90.0
  print('Total: ${added.total}'); // 1180.0

  // GST-inclusive price: split ₹1,180 for a sale to another state.
  final removed = GstCalculator.removeGST(
    amount: 1180,
    gstRate: 18,
    isInterState: true,
  );
  print('Base:  ${removed.baseAmount}'); // 1000.0
  print('IGST:  ${removed.igst}'); // 180.0

  // Invoice-ready values rounded to paise.
  final invoice = GstCalculator.addGST(
    amount: 99.99,
    gstRate: 5,
    fractionDigits: 2,
  );
  print(invoice); // cgst: 2.5, sgst: 2.5, total: 104.99

  // Invalid input throws an ArgumentError.
  try {
    GstCalculator.addGST(amount: 100, gstRate: -5);
  } on ArgumentError catch (e) {
    print('Error: ${e.message}');
  }
}