Everything you need to calculate GST correctly
Goods and Services Tax (GST) is an indirect tax charged on the supply of goods and services in India. This calculator helps you see the tax clearly, whether a quoted price is before or after GST.
How to calculate GST in India
For an exclusive price, multiply the price by the GST rate and add the result to the original price. For an inclusive price, divide the amount by 1 + GST rate / 100 to find the taxable value.
GST = Price × Rate ÷ 100
Final price = Price + GSTBase price = Inclusive price ÷ (1 + Rate ÷ 100)
GST = Inclusive price − Base priceExample: adding 18% GST
On a pre-tax price of ₹1,000, GST is ₹180. The final price is ₹1,180. For an intra-state sale, that is CGST of ₹90 and SGST of ₹90. An inter-state sale uses IGST of ₹180.
CGST, SGST and IGST explained
CGST and SGST apply together when a supply happens within the same state. The rate is split equally between them. IGST applies when goods or services move between states, and the full GST rate is shown as IGST.
GST rates in India
Common GST slabs are 0%, 5%, 12%, 18% and 28%. The right slab depends on the product or service classification, so use the rate printed on your invoice or confirm with a qualified professional.
Frequently asked questions
How do I add GST to a price?
Enter the pre-GST price, select Add GST and choose your rate. The calculator adds the tax and shows the final inclusive price.
How do I remove GST from an inclusive amount?
Select Remove GST, enter the amount that already includes tax and choose the rate. The result separates the original price from the GST component.
What is the GST on ₹1,000 at 18%?
GST is ₹180, making the total ₹1,180. It splits into ₹90 CGST and ₹90 SGST for an intra-state transaction.
Can I use this as a GST calculator for 12%?
Yes. Select 12% to calculate GST for a price, including the base amount, tax amount and final total.