What Is GST? A Complete Plain-English Guide to Goods and Services Tax in India

Since its landmark introduction on July 1, 2017, the Goods and Services Tax (GST) has fundamentally reshaped how taxation works in India. It replaced a chaotic web of more than 17 central and state taxes with a single, unified indirect tax system. Whether you are a consumer, freelancer, small business owner, or student preparing for an exam, understanding GST is essential to navigating India’s economy.

What Is GST?

GST is an indirect tax levied on the supply of goods and services across India. It is a destination-based, multi-stage tax — meaning it is charged at every stage of the supply chain (manufacture, wholesale, retail) but ultimately borne only by the final consumer, because businesses at each stage claim credit for the GST they’ve already paid (Input Tax Credit).

Types of GST: CGST, SGST, and IGST

CGST (Central GST): Collected by the Central Government on intra-state (within the same state) transactions
SGST (State GST): Collected by the State Government on intra-state transactions
IGST (Integrated GST): Collected by the Central Government on inter-state transactions (and imports), then apportioned between Centre and the destination state

When a transaction is within the same state, both CGST and SGST apply — each at half the total GST rate. For inter-state transactions, only IGST applies at the full rate.

GST Rate Structure

GST Rate	What’s Covered	Examples
0%	Essential goods and services	Fresh vegetables, milk, eggs, healthcare, education
5%	Basic necessities, mass consumption	Packaged food, small restaurants, economy hotels
12%	Standard goods and services	Processed food, business class air travel, branded apparel
18%	Most goods and services	Electronics, FMCG products, professional services, IT services
28%	Luxury and sin goods	Luxury cars, tobacco, aerated drinks, casinos

Calculate the exact GST on any product or service instantly with our free GST Calculator.

Input Tax Credit (ITC): The Core GST Mechanism

Input Tax Credit allows businesses to deduct the GST they paid on purchases (inputs) from the GST they collect on sales (output). This prevents the “tax on tax” (cascading effect) problem that plagued the old system.

Example: A manufacturer pays 18% GST on raw materials worth ₹1,00,000 (paying ₹18,000 GST). They sell the finished product for ₹1,50,000 and collect 18% GST (₹27,000). Their net GST payable to the government = ₹27,000 − ₹18,000 = ₹9,000. The ₹18,000 they paid earlier is their Input Tax Credit.

GST Registration: Who Needs It?

Mandatory GST registration is required if your annual aggregate turnover exceeds:

₹40 lakh for goods suppliers (₹20 lakh in special category states)
₹20 lakh for service providers (₹10 lakh in special category states)

Registration is also mandatory regardless of turnover for: inter-state suppliers, e-commerce sellers, casual taxable persons, and those liable to pay tax under reverse charge.

Composition Scheme: Simplified GST for Small Businesses

Small businesses with turnover up to ₹1.5 crore (₹75 lakh for services) can opt for the Composition Scheme. Instead of complex GST filings, they pay a flat percentage of turnover (1–6% depending on business type) with minimal compliance. Trade-off: they cannot claim ITC or charge GST on customer invoices.

How to Calculate GST

Adding GST: Amount including GST = Original price × (1 + GST rate/100)
Removing GST from inclusive price: Original price = Inclusive price / (1 + GST rate/100)

Our GST Calculator handles both directions instantly — add GST to a base price or extract GST from an inclusive amount.

Related Calculators

Disclaimer: GST rates and rules are subject to change by the GST Council. Always verify current rates and compliance requirements with a qualified CA or the official GST portal (gst.gov.in).