GST Suite
IGST Calculator: Integrated GST on Inter-State Sales
Calculate Integrated GST on inter-state sales, imports, and SEZ supplies under India's 0%, 5%, 18%, and 40% slabs. Learn when to charge IGST vs CGST/SGST.
IGST Calculator (Inter-State Supply)
Calculate Integrated Goods and Services Tax (IGST) for inter-state commercial transactions, imports, and SEZ supplies.
When does IGST apply?
Under Section 7 of the IGST Act 2017, IGST applies when the Location of the Supplier and the Place of Supply are in different States, different Union Territories, or a State and Union Territory, as well as on imports and supplies to Special Economic Zones (SEZ).
Purpose
Calculates Integrated GST (IGST) collected by the Central Government and apportioned to the consuming destination state.
Formula
IGST Amount = (Taxable Transaction Value × Applicable GST Rate) ÷ 100What is IGST?
The IGST Calculator computes Integrated Goods and Services Tax on inter-state commercial supplies, cross-border imports, and supplies to Special Economic Zone (SEZ) developers or units under Section 5 of the Integrated Goods and Services Tax (IGST) Act 2017. Unlike intra-state sales which split into equal CGST and SGST components, an inter-state transaction attracts a single unified IGST levy administered by the Central Government and apportioned to the destination consumption state. Determining whether a supply is inter-state depends on statutory Place of Supply rules under Sections 7 through 13 of the IGST Act: when the location of the supplier and the place of supply are in different States or Union Territories, IGST applies across India's active rate slabs (0%, 5%, 18%, 40%) and legacy rates (12%, 28%).
How It Works
Available Calculation Modes
Mode 1: Inter-State IGST Calculation
IGST Amount = (Taxable Value × GST Rate) ÷ 100 | Gross Total = Taxable Value + IGST Amount
Calculates unified Integrated GST on transactions crossing state boundaries or involving imports and SEZs.
Verified Worked Examples
Example 1: Standard Rate Inter-State Supply (18% Slab)
Rate: 18%A digital agency in Bengaluru (Karnataka) provides software services to an enterprise client in Gurugram (Haryana) for ₹10,000.00.
Because supplier is in Karnataka and place of supply is Haryana, Section 7 of the IGST Act mandates a single 18% IGST levy of ₹1,800.00, giving a gross invoice of ₹11,800.00.
Example 2: Fractional Decimal Inter-State Supply (5% Merit Rate)
Rate: 5%A textile manufacturer in Surat (Gujarat) ships yarn valued at ₹1,234.56 to a garment unit in Jaipur (Rajasthan) at the 5% merit slab.
At 5% IGST on ₹1,234.56, tax equals ₹61.73 after statutory rounding under Rule 26. Gross invoice total payable by the buyer is ₹1,296.29.
Example 3: Special Luxury Inter-State Supply (40% Slab)
Rate: 40%A luxury distributor in Delhi delivers premium recreational vehicles valued at ₹10,000.00 to a customer in Chandigarh.
The inter-state supply attracts 40% IGST totaling ₹4,000.00, producing a final invoice amount of ₹14,000.00. (Legacy 12% and 28% slabs apply exclusively to past invoice audits).
Official Rate Slabs & Statutory Coverage
| Tax Slab | Coverage & Applications | Statutory Status |
|---|---|---|
| 0% (Nil Rate) | Inter-state movement of exempt fresh produce, essential grains | Current Statutory Slab |
| 5% (Merit Rate) | Inter-state supplies of basic edible staples, bulk transport | Current Statutory Slab |
| 18% (Standard Rate) | Inter-state IT, software, consulting, commercial merchandise | Current Standard Slab |
| 40% (Special Rate) | Inter-state luxury automobiles, yachts, demerit commodities | Current Special Slab |
| 12% (Legacy Rate) | Historical invoices only (prior to rate rationalization) | Historical Reconciliation Only |
| 28% (Legacy Rate) | Historical invoices only (prior to rate rationalization) | Historical Reconciliation Only |
Common Calculation Mistakes & Legal Traps
⚠ Using Billing Address Instead of Place of Supply
Under Sections 10 and 12 of the IGST Act, tax determination is governed by the statutory Place of Supply (where goods are delivered or services performed), not simply the client's corporate billing address.
⚠ Charging CGST/SGST on Supplies to SEZ Units
Under Section 7(5)(b) of the IGST Act 2017, any supply of goods or services to or by a Special Economic Zone (SEZ) developer or unit is statutorily deemed an inter-state supply, requiring IGST.
⚠ Levying IGST on Cross-Border Merchanting Trade
Under Schedule III of the CGST Act, supply of goods from a non-taxable territory to another non-taxable territory without entering India is neither a supply of goods nor services; charging IGST is incorrect.
When to Use This
Use this calculator whenever you execute commercial transactions across state borders in India, invoice out-of-state corporate clients, supply SEZ developers, or calculate customs IGST on imported goods.
Why Use This Tool?
Incorrectly charging CGST/SGST instead of IGST deprives your out-of-state corporate client of claiming seamless Input Tax Credit in their home jurisdiction. This causes invoice rejections, delayed payments, and administrative corrections under Section 77.
All rate structures, formulas, and statutory provisions are cross-referenced with the Central Goods and Services Tax Act 2017, Integrated Goods and Services Tax Act 2017, and official circulars published by the Central Board of Indirect Taxes and Customs (CBIC).
Data privacy is guaranteed: all calculations run directly in your browser session and are never stored or shared with external parties.
Frequently Asked Questions
When is IGST charged instead of CGST and SGST?
IGST is charged whenever the location of the supplier and the statutory Place of Supply are in two different States, two different Union Territories, or a State and Union Territory. It also applies to imported goods and services and supplies to SEZs.
Who collects IGST and how is it distributed?
IGST is collected by the Central Government. Under Article 269A of the Constitution of India, the tax is subsequently apportioned between the Central Government and the destination State where goods or services are consumed.
How does Input Tax Credit work for IGST?
Under Section 49, 49A, and 49B of the CGST Act and Rule 88A, IGST credit must be completely exhausted first to pay IGST liability, and any remaining balance can be used to pay CGST and SGST in any proportion.
Are supplies to Special Economic Zones (SEZs) charged IGST?
Under Section 7(5)(b) of the IGST Act, supplies to SEZ developers or units are treated as inter-state supplies. They can be supplied as zero-rated under Letter of Undertaking (LUT) without tax, or with IGST payment subject to refund.
How is IGST calculated on imported goods?
Under Section 3(7) of the Customs Tariff Act 1975, IGST is levied on the assessable customs value plus basic customs duty and applicable social welfare surcharges.