GST Tools
GST Calculator – Calculate GST Online
Add GST to a base amount or extract GST from a GST-inclusive price, with CGST/SGST or IGST breakdown for every GST slab.
Result
- Base amount (excl. GST)
- ₹10,000.00
- CGST @ 9%
- ₹900.00
- SGST @ 9%
- ₹900.00
- Total GST
- ₹1,800.00
- Total amount (incl. GST)
- ₹11,800.00
How GST is calculated
To add GST: GST amount = base × rate ÷ 100. To remove GST from an inclusive amount: base = inclusive ÷ (1 + rate ÷ 100).
For supplies within the same state, GST splits equally into CGST and SGST. For inter-state supplies the full amount is charged as IGST.
GST calculation formulas
Exclusive (add GST): GST = taxable value × rate ÷ 100, and the invoice total = taxable value + GST.
Inclusive (reverse GST): taxable value = inclusive price ÷ (1 + rate ÷ 100), and GST = inclusive price − taxable value.
CGST / SGST: each is half of the total GST on an intra-state supply. IGST is the full GST on an inter-state supply.
Frequently asked questions
How is GST calculated on an amount?
GST amount = taxable value × GST rate ÷ 100. For example, ₹10,000 at 18% GST is ₹1,800 GST and ₹11,800 total.
How do I calculate GST in reverse from an inclusive price?
Divide the GST-inclusive price by (1 + rate ÷ 100) to get the taxable value. The difference between the two is the GST amount. ₹11,800 at 18% gives a base of ₹10,000.
When is GST split into CGST and SGST instead of IGST?
For supplies within the same state, GST is split equally into CGST and SGST. For inter-state supplies the entire amount is charged as IGST.
What GST rates apply in India?
The main GST slabs are 0%, 5%, 12%, 18% and 28%. The correct slab depends on the HSN code of the goods or the SAC code of the service.
Is this GST calculator free?
Yes. The calculator runs entirely in your browser, needs no sign-up and stores nothing you type.