GST Calculator (Add or Remove GST)
By Santaji GadepatilinUpdated October 27, 2026
Goods and Services Tax is added to the price of most goods and services in India. This calculator adds GST to a price or extracts it from a GST-inclusive price.
How to use the GST calculator
- Enter the amount.
- Pick the GST rate that applies to the product or service.
- Choose whether the amount is before GST (you want to add GST) or including GST (you want to find the GST inside it).
You get the price before GST, the GST amount, the CGST and SGST split and the final price.
GST formulas
Adding GST
GST = Price × Rate · Total = Price × (1 + Rate)
Removing GST (reverse calculation)
Price before GST = Inclusive price ÷ (1 + Rate)
A common mistake is to take 18% of the inclusive price. On ₹11,800 that gives ₹2,124, which is wrong. The GST inside ₹11,800 is only ₹1,800.
Worked examples
Adding 18% GST to ₹10,000
- GST = 10,000 × 0.18 = ₹1,800
- CGST = ₹900, SGST = ₹900
- Total = ₹11,800
Removing 5% GST from ₹2,100
- Price before GST = 2,100 ÷ 1.05 = ₹2,000
- GST = ₹100 (₹50 CGST + ₹50 SGST)
GST on ₹10,000 at each rate
| Rate | GST | Total price |
|---|---|---|
| 5% | ₹500 | ₹10,500 |
| 18% | ₹1,800 | ₹11,800 |
| 40% | ₹4,000 | ₹14,000 |
| 3% | ₹300 | ₹10,300 |
Current GST slabs in India
GST 2.0, effective 22 September 2025, simplified the structure:
- 0% (exempt): many essentials, education and healthcare services, individual life and health insurance.
- 5%: everyday essentials and many key inputs.
- 18%: the standard rate for most goods and services.
- 40%: luxury and sin goods.
- Special rates: 3% on gold, silver and jewellery, 0.25% on rough diamonds and a few others.
Rates for a specific item depend on its HSN or SAC code. Check the CBIC rate notifications or your accountant for the exact rate.
CGST, SGST and IGST
- Intra-state sale (seller and buyer in the same state): GST is split equally, half CGST and half SGST (or UTGST in a union territory).
- Inter-state sale or import: the full rate is charged as IGST.
The total tax is the same either way. Only the split and who receives the tax change.
Keep in mind
- Registered businesses can usually claim input tax credit for GST paid on purchases.
- Round the final invoice as your billing software requires.
- This calculator is for estimates. Use official notifications for filing and compliance.
Frequently asked questions
How do I calculate GST on an amount?
Multiply the price before GST by the rate. ₹10,000 at 18% gives GST of ₹1,800 and a total of ₹11,800.
How do I remove GST from an inclusive price?
Divide the inclusive price by (1 + rate). ₹11,800 ÷ 1.18 = ₹10,000, so the GST in it is ₹1,800. Choose “Including GST” in the calculator to do this.
What are the GST rates in India now?
Since GST 2.0 took effect on 22 September 2025 the main slabs are 5% and 18%, with 40% for luxury and sin goods. Special rates such as 3% for gold and 0.25% for rough diamonds still apply, and some items are exempt.
What is the difference between CGST, SGST and IGST?
Within a state, GST is split equally into CGST (central) and SGST (state). For sales between states the full amount is charged as IGST.
Is 18% GST split as 9% CGST and 9% SGST?
Yes, for an intra-state sale. For an inter-state sale it is 18% IGST.