GST Calculator
Add GST to a base price or remove GST from an inclusive price. Get the CGST/SGST breakup instantly for invoices and billing.
| Base amount (before GST) | ₹10,000.00 |
| CGST (9%) | ₹900.00 |
| SGST (9%) | ₹900.00 |
| Total GST (18%) | ₹1,800.00 |
| Total amount (with GST) | ₹11,800.00 |
For inter-state supply, the total GST applies as IGST instead of the CGST + SGST split.
How to use
- 1Enter the amount.
- 2Pick the GST rate — 5%, 12%, 18% or 28%.
- 3Choose “Add GST” if your amount excludes tax, or “Remove GST” if it already includes it.
- 4Read the base amount, the CGST and SGST halves, and the total.
Frequently Asked Questions
How do I remove GST from an amount?
To find the base amount from a GST-inclusive price, divide by (1 + rate/100). For example, ₹1,180 at 18% GST → 1180 ÷ 1.18 = ₹1,000 base and ₹180 GST. Choose 'Remove GST' mode above and this is done for you.
What is the CGST/SGST split?
For sales within the same state, GST is split equally between the Centre (CGST) and the State (SGST). An 18% GST becomes 9% CGST + 9% SGST. For inter-state sales the whole amount is charged as IGST.
What are the GST rates in India?
The main GST slabs are 0%, 5%, 12%, 18% and 28%, with special rates like 0.25% (rough diamonds) and 3% (gold). Rates change through GST Council decisions, so check the current rate for your product or service.
When is IGST charged instead of CGST and SGST?
On inter-state supplies. If the buyer and seller are in different states, the whole tax is IGST at the full rate. Within one state it is split equally into CGST and SGST, which is the split shown here.
Is GST calculated before or after a discount?
After. GST applies to the actual transaction value, so a discount shown on the invoice reduces the taxable amount. A discount given later, outside the invoice, generally does not.
Why does removing GST not mean subtracting the rate?
Because the rate was applied to the smaller base amount, not to the total. To strip 18% from ₹1,180 you divide by 1.18 to get ₹1,000 — subtracting 18% would wrongly give ₹967.60.