How is GST calculated in India?

For Exclusive GST (Add GST): GST Amount = (Base Amount × GST%) / 100, Total = Base Amount + GST Amount. For Inclusive GST (Remove GST): Base Amount = Total Amount / (1 + GST% / 100), GST Amount = Total Amount - Base Amount.

What is the difference between CGST, SGST, and IGST?

When goods/services are supplied within the same state (Intra-state), GST is split equally between CGST (Central GST) and SGST (State GST). When supplied across state borders (Inter-state), the entire tax is levied as IGST (Integrated GST).

What are the standard GST rate slabs in India?

Following the 56th GST Council meeting, the GST 2.0 structure took effect on 22 September 2025 with four principal rates: 0% (essential goods, most healthcare and education, individual life and health insurance), 5% (mass-consumption goods and daily necessities), 18% (the standard rate covering most services and manufactured goods), and 40% (demerit rate for sin and luxury goods such as pan masala, aerated beverages, larger cars, and motorcycles above 350cc). The earlier 12% and 28% slabs were largely merged into 5% and 18%, with a few residual items and the pending tobacco notification still at the older rates. Confirm the rate for a specific HSN or SAC code against the current CBIC notification.

Does this calculator store any financial inputs?

No. Toolbox runs 100% in your browser memory. No amounts, business figures, or calculations are logged or sent to any server.

Calculators

GST Calculator

Calculate Goods & Services Tax (GST) in India with support for Add GST, Reverse GST, CGST/SGST/IGST splits, and standard rate slabs.

Quick Answer & Summary

A GST Tax Calculator is an Indian Goods and Services Tax computation utility that calculates gross invoice values, net base prices, and exact tax distributions across standard statutory GST slabs (0%, 5%, 18%, and 40% under the GST 2.0 structure effective 22 September 2025, with 12% and 28% retained only for residual items). It provides both forward GST calculation (adding tax to a net base price) and reverse GST extraction (deducting embedded GST from a gross total), while automatically splitting taxes into Central GST (CGST 50%) and State GST (SGST 50%) for intra-state transactions, or Integrated GST (IGST 100%) for interstate trade. Indian business owners, chartered accountants, freelance professionals, and billing clerks use this calculator to prepare compliant GST tax invoices, verify vendor bills, calculate Input Tax Credit (ITC), and cross-check retail point-of-sale pricing. Running 100% client-side in your browser, all billing totals, product valuations, and tax math remain completely private and unlogged.

GST Tax Calculation Formulas

GST Amount = (Base_Price * GST_Rate) / 100 | Pre-GST Base = Total / (1 + GST_Rate / 100)

For intra-state sales, GST is divided equally into CGST (50%) and SGST (50%).

GST Calculator Inputs

Instant & Client-Side

Calculate GST addition, removal (reverse GST), and state tax splits.

Calculation Mode

Base Amount / Net Price (₹)

₹

GST Rate (%)18%

Standard Slabs:

Legacy (pre 22 Sep 2025):

Supply Destination

Tax Breakdown SummaryRate applied: 18%

Total Payable Amount

₹11,800

Total GST Included: ₹1,800

Net Amount (Base Price):

₹10,000

Total GST (18%):

₹1,800

↳ Central GST (CGST 9%):₹900

↳ State GST (SGST 9%):₹900

Gross Total Amount:

₹11,800

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Updated: September 2026

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Documentation & Guide

How to Use GST Calculator

Choose Calculation Mode

Select "Add GST" to calculate gross price from a net base price, or "Remove GST" (Reverse GST) to extract the tax component from an MRP/gross amount.

Enter Amount & Select Rate Slab

Enter the currency amount and click a current GST slab (0%, 5%, 18%, 40%), a legacy rate (12%, 28%) for older invoices, or type a custom tax percentage.

Review CGST, SGST, & IGST Breakdown

Toggle Intra-state vs Inter-state supply to inspect the exact Central, State, or Integrated GST splits.

Pro Tips

Use "Remove GST" to calculate the pre-tax price when checking an MRP invoice.

Click the current slab buttons (0%, 5%, 18%, 40%) for one-click rate configuration; the dashed legacy buttons (12%, 28%) cover invoices dated before 22 September 2025.

Click the copy icons next to any value to copy formatted amounts directly.

Practical Examples & Conversions

Input

Net Amount: ₹50,000 | Rate: 18% | Mode: Add GST

Output

GST: ₹9,000 (CGST: ₹4,500, SGST: ₹4,500) | Total: ₹59,000

Frequently Asked Questions (PAA)

In-Depth Architectural Guide

Calculators 6 min read

GST Calculation in India After GST 2.0: Slabs, Reverse GST, and CGST/SGST Splits

Calculate GST under the 0%, 5%, 18%, and 40% structure effective 22 September 2025. Covers forward and reverse GST formulas, intra-state versus inter-state splits, and invoice rounding rules.

Read Full Tutorial

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Authoritative Standards & Citations

Calculations and algorithms on this page are implemented and verified in strict accordance with the following official technical specifications:

IEEE Standards Association

IEEE 754: Standard for Floating-Point Arithmetic

Industry standard for floating-point computation formats, rounding rules, and arithmetic.

Reserve Bank of India

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Standardized interest compounding frequency and EMI calculation guidelines.