Add GST to a net price in seconds. Enter the amount before tax and the GST rate, such as 5% or 18%, to get the tax, the CGST and SGST split and the total price.

What is the GST Calculator?

This GST calculator adds tax to a price that does not include it yet. Type the before-tax amount and the GST rate, and it returns the final price including GST, the tax amount, an equal CGST and SGST split and the net price. It works for the current Indian GST rates of 5% and 18%, the 40% rate on select luxury and sin goods, and any other rate you enter, so you can also use it for VAT or sales tax in other countries.

Small business owners use it to prepare quotations and invoices, freelancers to bill clients, and buyers to check whether a quoted price is fair once tax is added. The tool does plain arithmetic on the rate you supply: it does not look up HSN codes or decide which slab applies. The CGST and SGST lines show the intra-state split, half the tax each; for an inter-state sale the whole tax amount is charged as IGST instead.

How to use the GST Calculator

Enter the price without tax in the Before-tax amount field, for example 1000.
Type the GST or sales tax rate in Tax rate (%), such as 5, 18 or 40.
Press Calculate to see the Total including tax, with the Tax, the CGST and SGST split and the Net price listed below it.
For an intra-state supply, use the CGST and SGST figures as shown; for an inter-state supply, charge the full Tax figure as IGST.
Copy the result for your invoice or quote, or press Reset to calculate another item.

Features

Adds any flat percentage tax to a before-tax price
Shows the tax amount, the tax-inclusive total and the net price together
Works with GST slabs, VAT or US-style sales tax rates
Equal CGST and SGST split for intra-state sales
Plain-language error messages and amounts shown with 2 decimals and Indian digit grouping

Why use this gst calculator

Prepare accurate quotes and invoices quickly
Know the true final price before you buy
Avoid errors when adding tax by hand
Free to use, private and runs right in your browser

Formula used

Tax = before-tax amount×rate/100; total = amount+tax.

Examples

18% GST on a ₹1,000 service

Input: Before-tax amount 1000, Tax rate 18%

Result: Total including tax: 1,180.00 Tax: 180.00 CGST: 90.00 and SGST: 90.00 (intra-state split) Net price: 1,000.00 The customer pays ₹1,180; for an intra-state sale that is ₹90 CGST plus ₹90 SGST.

5% GST on a ₹2,500 item

Input: Before-tax amount 2500, Tax rate 5%

Result: Total including tax: 2,625.00 Tax: 125.00 CGST: 62.50 and SGST: 62.50 (intra-state split) Net price: 2,500.00 GST adds ₹125 to the price.

40% GST on a luxury item

Input: Before-tax amount 45000, Tax rate 40%

Result: Total including tax: 63,000.00 Tax: 18,000.00 CGST: 9,000.00 and SGST: 9,000.00 (intra-state split) Net price: 45,000.00 The final price is ₹63,000.

Results are estimates for general information, not financial, medical, legal, tax, or property advice. Confirm important figures with the relevant institution or a qualified professional.

GST Calculator: frequently asked questions

How do I add GST to a price?

Multiply the before-tax price by the GST rate and divide by 100 to get the tax, then add it to the price. For ₹1,000 at 18%, the GST is ₹180 and the total is ₹1,180. A quick shortcut is to multiply the price by 1.18 for 18%, 1.05 for 5% or 1.40 for 40%. The calculator does this for you and shows the tax, CGST, SGST and net price separately.

Which GST rate should I use?

Since 22 September 2025 most goods and services in India fall under 5% or 18%, with a 40% rate for select luxury and sin goods, but the applicable rate depends on the goods or service, its HSN or SAC code and current government notifications, which change from time to time. This tool does not look up or verify rates; it simply applies the percentage you enter. Check the latest official GST rate schedule or ask your accountant before preparing a tax invoice.

How are CGST and SGST calculated from the total GST?

For a sale within the same state, the GST is split equally into CGST and SGST. So 18% GST becomes 9% CGST plus 9% SGST, and a tax of ₹180 becomes ₹90 each. The calculator shows this split automatically on the line CGST: 90.00 and SGST: 90.00 (intra-state split). For inter-state sales, the full tax amount is charged as IGST, so use the Tax figure instead.

My price already includes GST. Can I use this tool?

Not for that case. This calculator adds tax on top of a net price. If the amount you have is already inclusive of GST, use the Reverse GST Calculator, which divides the total by (1 + rate ÷ 100) to find the original price and the tax inside it. Simply taking 18% of an inclusive price would overstate the tax.

Can I use this as a VAT or sales tax calculator outside India?

Yes. The maths is the same for any flat percentage tax, so you can enter a VAT rate such as 20% or a local sales tax rate. Enter plain numbers without currency symbols. It does not handle compound taxes, tax-on-tax rules or local exemptions, so check those with your local tax authority.