How to use the GST calculator
- Choose Add GST for a price before tax, or Remove GST for a price that already includes it.
- Enter the amount and pick the GST rate.
- Choose whether the buyer is in the same state or another state.
- Read the taxable value, GST and total, with the CGST and SGST or IGST split.
- For an invoice, add each item with its rate to get GST by rate and the invoice total.
GST formulas
| To work out | Formula |
|---|---|
| GST to add | Price × rate ÷ 100 |
| Price with GST | Price × (100 + rate) ÷ 100 |
| Price before GST | Inclusive price × 100 ÷ (100 + rate) |
| GST inside a price | Inclusive price − price before GST |
GST calculation examples
- Adding 18% to ₹10,000: GST is ₹1,800 (₹900 CGST + ₹900 SGST), total ₹11,800.
- Removing 18% from ₹11,800: the price before GST is ₹10,000 and the GST inside it is ₹1,800.
GST rates after GST 2.0
From 22 September 2025, the GST Council replaced the 5%, 12%, 18% and 28% structure with two main slabs and a special rate. Typical examples:
| Rate | Typical goods and services |
|---|---|
| 0% | Fresh milk, paneer, most life-saving drugs, education services, individual life and health insurance |
| 3% | Gold, silver and jewellery |
| 5% | Everyday essentials such as packaged food staples, soaps, toothpaste, and many items earlier at 12% |
| 18% | Most goods and services, including small cars, ACs, TVs, and most professional services |
| 40% | Luxury and sin goods such as pan masala, aerated drinks and large cars |
Rates depend on the exact HSN or SAC code, so check the official CBIC rate list for your product before invoicing.
Related tools
Work out your income tax with the income tax calculator or your take-home pay with the salary calculator.
Frequently asked questions
How do I calculate GST on an amount?
Multiply the price before tax by the GST rate and divide by 100. For ₹10,000 at 18%, GST is ₹1,800 and the total is ₹11,800.
How do I remove GST from a price that includes it?
Divide the GST-inclusive price by (100 + rate) and multiply by 100 to get the price before tax. For ₹11,800 at 18%: 11,800 × 100 ÷ 118 = ₹10,000, so the GST is ₹1,800.
What are the GST rates in 2026?
Since 22 September 2025 most goods and services fall into 5% (essentials) or 18% (standard). A special 40% rate applies to luxury and sin goods. Some items are exempt (0%), and gold and silver jewellery attract 3%. The 12% and 28% slabs were removed for most items.
What is the difference between CGST, SGST and IGST?
For a sale within a state, GST is split equally between the Centre (CGST) and the state (SGST, or UTGST in a union territory). For a sale to another state, the whole amount is charged as IGST. The total tax is the same.
Who needs to register for GST?
Businesses supplying goods generally need to register once annual turnover crosses ₹40 lakh (₹20 lakh in some states), and service providers at ₹20 lakh (₹10 lakh in special category states). Some businesses, such as e-commerce sellers and inter-state suppliers, must register regardless of turnover.
Is GST charged on GST?
No. GST is charged on the taxable value only. Other charges such as packing or delivery that are part of the supply are included in the taxable value before GST is added.