GST has been around since 2017 and most people still fumble the calculation. Not because it's complicated โ it's actually quite simple โ but because nobody sat down and explained the logic clearly. So here's a quick, practical guide for anyone who's ever looked at an invoice and thought "wait, is this price with GST or without?"
What GST Actually Is
Before 2017, India had a patchwork of indirect taxes like VAT, service tax, excise duty, octroi, entry tax, each collected at different stages by different authorities. It was genuinely confusing and created what economists call a "cascading effect," meaning you were effectively paying tax on tax.
GST replaced all of that with a single unified tax. One rate, applied at each stage of the supply chain, with credit available for taxes already paid earlier. For consumers, GST is simply included in the final price of most things they buy.
The GST Slabs You Need to Know
India uses four main GST rates: 0%, 5%, 12%, 18%, and 28%. Here's a practical breakdown:
0% on fresh vegetables, milk, eggs, cereals, most unprocessed staples. Also most basic healthcare and educational services.
5% on packaged food items, frozen vegetables, tea, coffee, sugar, economy air travel, basic household items.
12% on processed food, computers, business class travel, construction work contracts, some medicines.
18% - This is the big one. Covers most services like IT, consulting, restaurant food (AC), telecom, banking, insurance, and a large chunk of manufactured goods.
28% on luxury items, aerated drinks, tobacco, automobiles, and some real estate transactions.
Gold and precious metals get a special 3% slab. Small businesses below certain turnover thresholds can use the composition scheme at much lower flat rates.
How GST Calculation Actually Works
GST Amount = Base Price ร (GST Rate รท 100)
Final Price = Base Price + GST Amount
Removing GST (Price is including GST):
Base Price = GST-Inclusive Price รท (1 + GST Rate รท 100)
GST Amount = GST-Inclusive Price โ Base Price
Example at 18%:
Add GST: โน1,000 + 18% = โน1,180
Remove GST: โน1,180 รท 1.18 = โน1,000
you can handles both type tax while using our gst calculator
CGST, SGST, IGST - What's the Difference?
This trips up a lot of small business owners when generating invoices.
When a sale happens within the same state (intra-state), the GST is split equally: half goes to the central government as CGST, half to the state government as SGST. So an 18% GST charge on an intra-state invoice appears as 9% CGST + 9% SGST.
When goods or services cross state borders (inter-state), the full GST is collected as IGST - which the central government then distributes to the concerned states. Putting the wrong type on an invoice can create input credit complications, so this distinction genuinely matters for businesses.
Freelancers and GST: What You Need to Know
If your annual revenue from freelance or professional work crosses โน20 lakh (โน10 lakh in some states), GST registration becomes mandatory. Below that threshold it's optional, but registering can be useful if your clients are businesses who want to claim input credit.
Most professional services โ software development, design, consulting, digital marketing โ attract 18% GST. When you raise an invoice, you add 18% on top of your fee and collect it from the client. You then deposit that amount with the government after adjusting for input GST you've paid on business expenses like software, internet, or a work laptop.
Speaking of which โ your salary or freelance income tax is a separate calculation altogether. Our income tax calculator handles that, and it's worth running both calculations to understand your total tax picture.
Input Tax Credit: Don't Leave Money on the Table
This is the feature most small business owners underutilise. Input Tax Credit (ITC) lets you offset the GST you've paid on your purchases against the GST you've collected from clients.
Say you collected โน18,000 in GST from clients this month but paid โน5,000 in GST on business purchases. Your actual GST deposit is only โน13,000. Over a year, proper ITC tracking can save a meaningful amount โ and it's legally your right to claim it.
GST on Home Loans and Real Estate
This is a common area of confusion. Under-construction residential properties attract 5% GST (1% for affordable housing). Ready-to-move properties with a completion certificate don't attract GST at all. Commercial properties under construction are taxed at 12%.
If you're buying a property and calculating the total cost including taxes, our home loan calculator can help you figure out the EMI on the loan component, while the GST calculator covers the tax part separately.
GST on Insurance Premiums
Health and life insurance premiums attract 18% GST. So if your annual health insurance premium is โน15,000, you actually pay โน17,700. The full amount โ including the GST portion โ is eligible for deduction under Section 80D when you file your income tax return, which partially offsets the cost.
Is GST charged on second-hand goods?
For registered dealers buying and selling used goods, GST applies only on the margin โ selling price minus buying price. Individual non-registered sellers don't need to charge GST on personal item sales, like selling an old phone or furniture.
What is the GST on restaurant food?
Non-AC and AC restaurants both charge 5% GST (without input tax credit). Restaurants in starred hotels where room tariff exceeds โน7,500 charge 18%. Swiggy and Zomato deliveries fall under 5% GST as well.
How do I know if a price is GST inclusive or exclusive?
In India, retail prices (MRP on packaged goods) are always GST inclusive โ the displayed price is what you pay. Business-to-business invoices usually show the base price with GST added separately. When in doubt, check the invoice line items โ if GST appears as a separate line, the base price was exclusive.
Can I get a GST refund as an individual consumer?
Generally, no. Registered businesses can claim refunds in specific scenarios โ exports, excess ITC, or payment errors. Individual consumers can't claim GST back unless the seller has overcharged and agrees to reverse it.
What is GST on online shopping โ Amazon, Flipkart etc.?
The GST on products sold through e-commerce platforms is the same as offline retail โ it depends on the product category. The platform itself collects Tax Collected at Source (TCS) at 1% from sellers, which sellers can claim as credit. As a buyer, you pay the same GST you'd pay in a physical store.
GST is really just arithmetic once you understand the logic. Use our GST calculator for quick calculations on any amount, and keep this guide handy when you need to understand what's behind the number.