GST Calculator: Add or Remove GST in One Step
Use this GST calculator to work out the tax on a sale or to take GST out of a price that already includes it. It also shows how the tax splits into CGST and SGST for a same-state sale, or IGST for a sale to another state.
Estimates for general information. This is not tax or accounting advice.
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From related categoriesHow to use this calculator
- Enter the amount.
- Enter the GST rate that applies to your goods or service.
- Choose whether the amount is before GST (add GST) or already includes GST (remove GST).
- Read the GST amount, the before-GST and with-GST values, and the CGST, SGST and IGST split.
The formula
Worked example
Add 18% GST to ₹10,000: GST = ₹1,800 and the total is ₹11,800. CGST and SGST are ₹900 each. Now remove 18% GST from ₹11,800: the amount before GST is ₹10,000 and the GST is ₹1,800.
Understanding your result
GST on a same-state sale is collected as two equal halves, CGST for the central government and SGST for the state. On an inter-state sale the whole amount is collected as IGST. The total tax is the same either way. Note that GST is about 15.25% of a price that includes 18% GST, not 18%.
When to use it
- Prepare a quick quotation or invoice total.
- Find the base price of an item you were quoted with GST included.
- Check the tax split shown on a supplier bill.
In-depth guide
GST on ₹10,000 at each rate
The table shows what happens to a ₹10,000 price before tax at the common rates.
| GST rate | GST amount | Total price | CGST + SGST (each) |
|---|---|---|---|
| 5% | ₹500 | ₹10,500 | ₹250 |
| 18% | ₹1,800 | ₹11,800 | ₹900 |
| 40% | ₹4,000 | ₹14,000 | ₹2,000 |
Adding GST and removing GST
To add GST, multiply the price by (1 + rate). For 18%, multiply by 1.18. To remove GST from a price that already includes it, divide by the same factor. For 18%, divide by 1.18.
A common mistake is to take 18% of the GST-inclusive price. Take ₹11,800: 18% of it is ₹2,124, which is wrong. The correct GST inside ₹11,800 is ₹11,800 − (₹11,800 ÷ 1.18) = ₹1,800.
| Price including GST | Rate | Price before GST | GST inside |
|---|---|---|---|
| ₹10,500 | 5% | ₹10,000 | ₹500 |
| ₹11,800 | 18% | ₹10,000 | ₹1,800 |
| ₹14,000 | 40% | ₹10,000 | ₹4,000 |
| ₹2,360 | 18% | ₹2,000 | ₹360 |
CGST, SGST and IGST
When the seller and the buyer are in the same state, the GST is split equally between the central government (CGST) and the state government (SGST). When goods or services move between states, a single IGST equal to the full rate applies. The total tax is the same either way. Only the split and the invoice lines differ.
Tips for invoices and pricing
- Decide whether your displayed price includes GST and say so clearly to customers.
- Round GST at the invoice level as your accounting software or accountant advises.
- Check the correct rate and classification for your item or service. The same product can fall under different rates depending on description.
- Keep your own records, because a calculator does not replace a tax return.
Limits
The calculator applies the rate you type and does not check whether it is the correct rate for your item. Cess, special schemes and rate changes are not included. For filing and compliance, confirm with a qualified professional.
Assumptions and limits
Assumes one GST rate for the whole amount. Cess, rounding rules on invoices, input tax credit and composition scheme rules are not included. GST rates are set by the GST Council and can change, so confirm the rate for your product or service (HSN or SAC code) before invoicing. This is not tax advice.
Frequently asked questions
What are the current GST rates in India?
After the GST 2.0 changes from 22 September 2025, the main slabs are 0%, 5%, 18% and 40%, with special rates such as 3% on gold. The older 12% and 28% rates may still appear on earlier invoices.
How do I remove GST from a price?
Divide the GST-inclusive price by 1 plus the rate. For 18%, divide by 1.18.
When do I charge CGST and SGST instead of IGST?
CGST and SGST apply when the supplier and the place of supply are in the same state. IGST applies for inter-state supply.
Can I enter a rate that is not on the list?
Yes. Type any rate, such as 3 or 0.25.
Is the result valid for filing returns?
It is an estimate. Use your accounting software and consult a tax professional for filing.