GST in India Explained: Rates, Calculation and How It Works

You pay GST many times a day, often without noticing it. It is in your restaurant bill, your phone recharge, your online shopping and almost every product on a shop shelf. For most people it is just a line on a receipt. Understanding it, though, is genuinely useful, whether you are a consumer checking a bill or a small business owner who needs to charge it correctly. This guide explains GST in plain language.

What is GST

GST stands for Goods and Services Tax. It is a single, nationwide tax on the supply of goods and services in India. It was introduced in July 2017 to replace a tangle of older taxes such as VAT, service tax and excise duty, which used to overlap and pile on top of each other.

The core idea of GST is one tax, charged at each stage of the supply chain, but with credit given for the tax already paid at earlier stages. The final burden lands on the end consumer, while businesses in the middle effectively pass it along. It is, in short, a tax on consumption.

The GST rate slabs

GST is charged at different rates for different goods and services. In September 2025, the rate structure was simplified in a reform widely called GST 2.0. The structure now centres on two main slabs:

A few special rates also exist for specific items, such as a low rate on gold. But for everyday purposes, the picture is simple: most things fall under 5 percent or 18 percent, essentials are nil-rated, and luxury and sin goods carry the top 40 percent rate. Our GST calculator handles any rate you choose.

CGST, SGST and IGST

Here is a part that confuses many people. GST is a tax shared between the central government and the state governments. How it is split depends on whether the sale is within one state or across states.

• CGST, Central GST. The central government's share of the tax.
• SGST, State GST. The state government's share of the tax.
• IGST, Integrated GST. Charged on inter-state sales, and later shared between the centre and states.

The rule is straightforward. For a sale within the same state, the GST is split equally into CGST and SGST. So an 18 percent GST appears on the bill as 9 percent CGST plus 9 percent SGST. For a sale between two different states, the same total is charged as a single IGST instead. The total tax you pay is identical either way. Only the labelling and the sharing change.

How to calculate GST

There are two everyday GST calculations, and both are simple.

Adding GST to a price

When you have a base price and need to add GST: GST amount equals the base price multiplied by the GST rate, divided by 100. The final price is the base price plus that GST amount. On a base of ₹2,000 at 18 percent, the GST is ₹360 and the final price is ₹2,360.

Removing GST from a total price

Sometimes a price already includes GST and you want to know the base. Here, base price equals the total divided by (1 plus the rate over 100). If ₹2,360 includes 18 percent GST, the base is 2,360 divided by 1.18, which is ₹2,000, and the GST portion is ₹360. Our GST calculator does both directions instantly, and shows the CGST and SGST split.

Who needs to register for GST

GST registration is mainly a concern for businesses, not individual consumers. A business generally must register for GST once its annual turnover crosses a threshold limit, and the threshold differs for goods and for services, and by state. Businesses below the threshold, and ordinary salaried individuals, do not need to register.

A registered business charges GST on its sales, can claim credit for the GST it paid on its purchases, called input tax credit, and files regular GST returns. If you run a small business, it is worth confirming the current threshold for your category and state, and registering if you cross it.

GST as a consumer: what to watch

• Check that GST is shown clearly on bills. A proper tax invoice shows the base amount and the GST separately.
• Know that the listed price may or may not include GST. For most retail products the displayed price is inclusive. For many services, GST is added on top, so the final bill is higher than the quoted figure.
• Be wary of GST being charged twice or at the wrong rate. Knowing the rough rate for what you are buying lets you spot an obviously wrong bill.

The bottom line

GST is a single tax on consumption, charged at rates that now centre on 5 percent and 18 percent, with nil for essentials and 40 percent for luxury and sin goods. Within a state it splits into CGST and SGST; across states it becomes IGST. To add GST, multiply the base by the rate. To remove it, divide the total by one plus the rate. That is most of what an ordinary person ever needs.

GST is the quiet companion of almost every purchase you make. Understanding it will not lower your bill, but it will help you read it.

Whether you are a consumer checking a receipt or a small business setting a price, the GST calculator takes the arithmetic off your hands and shows the CGST and SGST breakdown at a glance.