GST Calculator
Instantly add or remove GST to find your net amount, total tax, and gross price.
Adds GST to the base price to get the total.
Calculation Summary
How to use the GST Calculator
Select Mode
Choose "Add GST" if your price doesn't include tax yet, or "Remove GST" to extract the tax from a total final price.
Enter Amount & Rate
Input your numerical amount and click on the applicable GST rate (3%, 5%, 12%, 18%, 28%, or set a custom rate).
Get Breakdown
Click calculate to instantly see your Net Amount, Total Gross Price, and a neat breakdown of CGST and SGST.
GST Calculator Features
Forward & Reverse GST
Seamlessly calculate tax forwards (exclusive to inclusive) or perform reverse calculations (inclusive back to exclusive).
CGST / SGST Split
The tool automatically divides the total calculated GST equally into Central GST (CGST) and State GST (SGST) for accurate invoicing.
100% Private & Fast
All calculations happen instantly in your browser. No financial data is ever sent to or stored on our servers.
Frequently Asked Questions
To calculate GST manually, use this formula:
Add GST: GST Amount = (Base Cost * GST Rate) / 100.
Total Amount = Base Cost + GST Amount.
If you know the final total amount and want to extract the base cost before tax, the formula is:
Remove GST: Base Cost = Total Amount / (1 + (GST Rate / 100)).
GST Amount = Total Amount - Base Cost.
In India's dual GST model, intrastate sales (within the same state) are split equally between the Central Government and the State Government. CGST (Central Goods and Services Tax) is collected by the Centre, and SGST (State Goods and Services Tax) is collected by the State. They are simply 50% of the total GST each.
The primary GST slabs in India are 5%, 12%, 18%, and 28%. Certain special items, like rough precious stones, have lower rates like 3% or 0.25%, and essential items are often exempt (0%). The majority of services fall under the 18% tax bracket.
Yes! IGST (Integrated Goods and Services Tax) applies to interstate sales (between two different states) and is collected entirely by the Centre. The IGST amount is exactly equal to the "Total GST Amount" shown in our calculator results. Simply ignore the CGST/SGST split.
Absolutely not. This calculator runs 100% locally in your web browser using JavaScript. We do not track, log, or send any of the numbers you enter back to our servers. Your financial calculations remain completely private.