GST Calculator India: CGST, SGST & IGST Rates
Calculate GST amounts, pre-tax base prices, and CGST, SGST, or IGST tax splits across all Indian rate slabs.
How to Calculate GST in India (Add or Remove GST)
The Goods and Services Tax (GST) in India is a destination-based multi-stage consumption tax levied on the supply of goods and services. Enacted under the Constitution (One Hundred and First Amendment) Act, GST replaced cascading central and state levies, such as Central Excise Duty, Service Tax, State VAT, Entry Tax, and Luxury Tax, unifying the Indian market under a single indirect taxation framework.
For deeper analysis and related planning, you can also explore our Income Tax Calculator and Capital Gains Tax Calculator.
GST Calculation Formulas: Inclusive and Exclusive
Depending on whether a price quote is net of tax or inclusive of statutory levies (such as an MRP on consumer retail packaging), use these mathematical formulas:
GST Amount = Base Amount × (GST Rate / 100)
Gross Total = Base Amount + GST Amount = Base Amount × (1 + GST Rate / 100)
Intra-State Split: CGST = GST Amount / 2, SGST = GST Amount / 2
Inter-State: IGST = GST Amount
2. Removing GST (Reverse GST from Tax Inclusive Price):
Base Amount = Total Gross Amount / (1 + GST Rate / 100)
GST Amount = Total Gross Amount − Base Amount
Indian GST Slabs & HSN/SAC Category Overview
The GST Council classifies taxable items across statutory slabs based on economic essentiality:
| Slab Rate | Tax Split (Intra-State) | Tax Type (Inter-State) | Representative Commodities & Services |
|---|---|---|---|
| 0% (Nil) | 0% CGST + 0% SGST | 0% IGST | Fresh milk, unbranded grains, fresh fruits, vegetables, public healthcare |
| 0.25% & 3% | 0.125% CGST + 0.125% SGST | 0.25% / 3% IGST | Cut & polished diamonds (0.25%), gold, silver, and precious jewelry (3%) |
| 5% | 2.5% CGST + 2.5% SGST | 5% IGST | Packaged food staples, tea, coffee, edible oil, economy railway tickets |
| 12% | 6.0% CGST + 6.0% SGST | 12% IGST | Processed food products, computers, medical equipment, business class air travel |
| 18% | 9.0% CGST + 9.0% SGST | 18% IGST | Capital goods, IT software, telecom services, financial consulting, hotels |
| 28% (+ Cess) | 14.0% CGST + 14.0% SGST | 28% IGST | Automobiles, luxury motorcycles, air conditioners, aerated drinks, tobacco |
Input Tax Credit (ITC) Set Off Rules Under Rule 88A
A registered enterprise offsetting output tax liabilities against input credits must comply with the statutory hierarchy prescribed by Section 49 and Rule 88A of the CGST Rules:
| ITC Available | Step 1: Set Off Against | Step 2: Balance Off Against | Prohibited Cross-Utilization |
|---|---|---|---|
| IGST Credit | IGST Output Liability | CGST and SGST in any proportion | Must be completely exhausted first |
| CGST Credit | CGST Output Liability | IGST Output Liability | Cannot set off against SGST |
| SGST / UTGST Credit | SGST Output Liability | IGST Output Liability | Cannot set off against CGST |
Intra-State vs Inter-State Supply Example
Understanding supply destination prevents cross-border invoicing disputes:
- Intra-State Supply (e.g., Mumbai to Pune within Maharashtra): An electronics retailer sells components for ₹10,000 under the 18% slab. Tax owed is 9% CGST (₹900) + 9% SGST (₹900) = ₹1,800. Final invoice is ₹11,800.
- Inter-State Supply (e.g., Delhi to Bengaluru): The same ₹10,000 transaction billed across state borders incurs 18% IGST (₹1,800). The final invoice is also ₹11,800, with the tax remitted directly to the Central Government under Integrated GST.
Frequently Asked Questions
What is the formula to calculate GST?
To add GST, multiply the base amount by (GST Rate / 100). The total price equals Base Amount + GST Amount. To remove GST from a tax-inclusive total, Base Amount = Total Price / (1 + GST Rate / 100), and GST Amount = Total Price minus Base Amount.
How is Input Tax Credit (ITC) set off under Rule 88A?
Under GST Rule 88A, IGST credit must be completely exhausted first against IGST liability, and any remaining IGST credit can be utilized against CGST and SGST in any order and proportion. Only after IGST credit is zero can CGST credit (against CGST and IGST) and SGST credit (against SGST and IGST) be utilized. CGST credit can never be used to offset SGST liability, and vice versa.
What is the difference between CGST, SGST, and IGST?
Intra-state sales within the same state are split equally into CGST (Central Goods and Services Tax) and SGST (State Goods and Services Tax). Inter-state sales across state borders are charged as IGST (Integrated Goods and Services Tax) collected by the Centre.
What are the standard GST rate slabs in India?
India's GST structure features five primary tiers: 0% (essential fresh food and education), 5% (packaged staples and economy transport), 12% (processed foods and business class travel), 18% (standard capital goods, software, and industrial services), and 28% (luxury items, automobiles, and sin goods with cess).
What is the turnover threshold for GST registration in India?
For suppliers of goods, the mandatory GST registration threshold is ₹40 Lakhs annual aggregate turnover (₹20 Lakhs in special category states). For service providers, the mandatory threshold is ₹20 Lakhs (₹10 Lakhs in special category states).
What is the GST Composition Scheme limit?
Small businesses with annual aggregate turnover up to ₹1.5 Crore (₹75 Lakhs in North-Eastern states) can opt for the Composition Scheme, paying a flat turnover tax (1% for manufacturers/traders, 5% for restaurants) with simplified quarterly filings, without claiming input tax credits.