About the GST Calculator
This GST Calculator adds or removes Goods and Services Tax from any amount using the common Indian slabs of 5%, 12%, 18%, and 28%, and splits the tax into CGST and SGST for intra-state transactions. It is built for shopkeepers, freelancers, accountants, and anyone who needs a quick, accurate tax figure.
Add GST vs Remove GST
- Add GST: start with a base price and add tax on top to get the final gross amount the customer pays. Use this when your listed price is exclusive of tax.
- Remove GST: start with a tax-inclusive price and work out how much of it is tax and what the base value was. Use this when you have a final price and need the pre-tax figure for accounting.
How GST is calculated
To add GST, multiply the amount by the rate and divide by one hundred, then add it to the base. To remove GST from an inclusive price, divide the price by one hundred plus the rate, then multiply by one hundred to recover the base; the difference is the tax. For intra-state sales the total GST splits equally into CGST (central) and SGST (state), each being half of the total tax shown here.
Common uses
Businesses use it to price products correctly, prepare invoices, and reconcile tax-inclusive receipts. Buyers use it to understand how much tax sits inside a quoted price. Because the math is identical across all slabs, you simply pick the rate that applies to your goods or services.
Tips
Choose the slab that matches your product category, as different goods attract different rates. For inter-state supply the tax is IGST rather than split CGST/SGST, though the total is the same. To work out margins after tax, pair this with the Profit Margin Calculator, and for discounts the Discount Calculator. Everything runs in your browser, so your figures stay private.
Frequently Asked Questions
How is GST added to an amount?
GST amount = (Original amount x GST rate) / 100. The net amount is the original plus the GST.
How do I remove GST from a GST-inclusive price?
Original = Inclusive amount x 100 / (100 + rate). The difference is the GST component.
What is the CGST and SGST split?
For intra-state sales, GST splits equally into CGST and SGST, each half of the total GST.
Which GST slabs does this support?
The common Indian slabs: 5%, 12%, 18%, and 28%. Select the one that applies to your goods or services.
Does this calculation run on your servers?
No. The GST math runs entirely in your browser, so your figures never leave your device.