A fast, private GST calculator
Whether you are generating an invoice, checking a supplier's bill, or pricing a new product, this tool helps you instantly calculate the Goods and Services Tax. It functions as a complete GST calculator India, supporting standard tax slabs and accurately splitting the tax into the correct central and state components.
Because the math happens directly in your browser, your financial figures are never uploaded or saved to any server. You can safely calculate taxes for confidential client invoices or internal expense reports without worrying about data privacy.
Add GST vs. Remove GST
Depending on the information you have, you will need to calculate tax in one of two directions. This tool handles both seamlessly:
Add GST (Exclusive to Inclusive) Use this mode when you know the base price of a product or service and need to calculate the final price to charge your customer. The calculator applies the selected tax rate to the net amount, giving you the total tax to add to the invoice and the final gross amount.
Remove GST (Inclusive to Exclusive) Often called a reverse GST calculator, this mode is essential when you have a final receipt or Maximum Retail Price (MRP) and need to extract the tax amount. Working backward from a tax-inclusive price is not as simple as subtracting the tax percentage. The calculator uses the correct reverse-calculation formula to split the gross amount back into the original net price and the tax component, which is crucial for claiming Input Tax Credit (ITC).
Current GST rates in India
On 22 September 2025 India simplified its GST structure. Most goods and services now fall into two main slabs, 5% and 18%, with a special 40% rate for selected luxury and sin goods. Precious stones and metals keep their special rates of 0.25% and 3%. The previous 12% and 28% slabs were largely removed, but you may still need them to check invoices issued before the change. Rates depend on the exact item and can change, so confirm the applicable rate on the official GST portal or with your tax adviser.
The CGST / SGST Calculator Breakdown
In India's dual GST structure, the destination of the goods or services determines how the tax is collected and distributed. This calculator automatically formats the output based on the type of supply you select:
- Intra-state (Within the same state): For local sales, the total GST is divided equally between the Central Government and the State Government. If you select an 18% tax rate, the calculator will split the total tax amount into 9% CGST (Central Goods and Services Tax) and 9% SGST (State Goods and Services Tax) or UTGST (Union Territory GST).
- Inter-state (Between different states): For sales across state borders or imports/exports, the tax is collected as a single sum by the Central Government. If you select an 18% tax rate, the calculator will display the entire tax amount as 18% IGST (Integrated Goods and Services Tax).
How the GST formulas work
If you are building your own spreadsheets or want to verify the math manually, here are the formulas used by the calculator:
To Add GST:
Tax Amount = Net Amount × (GST Rate / 100)Gross Amount = Net Amount + Tax Amount
To Remove GST:
Net Amount = Gross Amount / (1 + (GST Rate / 100))Tax Amount = Gross Amount - Net Amount
For example, to remove an 18% GST from a gross amount of ₹1,180:
Net Amount = 1180 / (1 + 0.18) = 1180 / 1.18 = 1000Tax Amount = 1180 - 1000 = 180
When to use this tool
Invoicing clients: Quickly determine the exact CGST and SGST values to list on your tax invoices so your clients can claim their input tax credits without errors.
Pricing retail products: If you want to sell a product at a flat ₹999 including tax, use the remove GST feature to find out exactly what your base price should be for your accounting software. You can then use the Margin Calculator to ensure your base price still leaves room for profit.
Expense management: When logging business expenses from receipts that only show the final total, use the reverse calculation to separate the base expense from the recoverable tax.
Note: If you are calculating generic regional taxes outside of a GST framework, you may also find our standard Sales Tax Calculator or Discount Calculator helpful for your business needs.