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GST calculator: add or remove GST in seconds
Use this GST calculator to add GST to a price or take it out of a GST-inclusive total, and see the CGST and SGST or IGST split. Below it are the formulas with worked examples and the current GST rates, so you can check any figure by hand.
- Add GST to a price or remove it from a total
- CGST + SGST or IGST split
- Works as an inclusive and reverse GST calculator
- Current rate slabs after 22 September 2025
Free GST calculator online
- Taxable value
- ₹10,000.00
- CGST @ 9%
- ₹900.00
- SGST @ 9%
- ₹900.00
- Total GST
- ₹1,800.00
The GST rate depends on the HSN/SAC code of your goods or service. Check the notified rate before you invoice.
Enter the amount and choose the GST rate. Then pick whether the amount is before tax (add GST) or already includes tax (remove GST). Choose intra-state for a sale within your state, or inter-state for a sale to another state. You get the taxable value, the GST amount and its split, and the total.
GST formula with worked examples
- Adding GST to a price: GST = amount × rate ÷ 100. Total = amount + GST.
- Removing GST from an inclusive total: GST = amount − (amount × 100 ÷ (100 + rate)). Taxable value = amount − GST.
| Example | Calculation | Result |
|---|---|---|
| Add 18% GST to ₹10,000 | 10,000 × 18 ÷ 100 = 1,800 | GST ₹1,800, total ₹11,800 |
| Remove 18% GST from ₹11,800 | 11,800 × 100 ÷ 118 = 10,000 | Taxable value ₹10,000, GST ₹1,800 |
| Add 5% GST to ₹2,000 | 2,000 × 5 ÷ 100 = 100 | GST ₹100, total ₹2,100 |
| Remove 5% GST from ₹1,050 | 1,050 × 100 ÷ 105 = 1,000 | Taxable value ₹1,000, GST ₹50 |
| Remove 18% GST from ₹500 | 500 × 100 ÷ 118 = 423.73 | Taxable value ₹423.73, GST ₹76.27 |
Why not just take 18% off ₹11,800? Because 18% of ₹11,800 is ₹2,124, which is more than the tax inside the price. The tax was worked out on ₹10,000, not on the total, so you divide by 1.18 to get back to it. That is all an inclusive or reverse GST calculator does.
CGST + SGST or IGST: which applies?
The GST rate is the same either way. What changes is which government gets the tax. On a sale within the same state, the GST is split equally into CGST for the Centre and SGST for the state. In a Union territory without its own legislature, UTGST takes the place of SGST. On a sale to another state, the whole amount is IGST.
| Type of sale | Tax charged | Amount |
|---|---|---|
| Within the same state | CGST 9% + SGST 9% | CGST ₹900 + SGST ₹900 |
| To another state | IGST 18% | IGST ₹1,800 |
Whether a sale is intra-state or inter-state depends on the place of supply, not only on where the buyer is registered. For most sales of goods, it is where the delivery ends.
Current GST rates (after 22 September 2025)
At its 56th meeting on 3 September 2025, the GST Council replaced the old structure (5%, 12%, 18% and 28%). There are now two main rates, a merit rate of 5% and a standard rate of 18%, and a special rate of 40% for a small set of goods and services. The new rates took effect on 22 September 2025. For pan masala and tobacco products, the revised rates applied from 1 February 2026.
| Rate | Examples |
|---|---|
| Nil (0%) | Many essentials, such as UHT milk, packaged paneer, Indian breads like roti and paratha, and specified life-saving medicines |
| 5% (merit rate) | Most packaged foods, soap, shampoo and toothpaste, most medicines, tractors and farm machinery, hotel rooms up to ₹7,500 a night, and gym and salon services |
| 18% (standard rate) | Most other goods and services, including cement, TVs, air conditioners, small cars, motorcycles up to 350 cc and auto parts |
| 40% (special rate) | Specified sin and luxury items, such as pan masala, cigarettes and tobacco, aerated drinks, larger cars, motorcycles above 350 cc, yachts and private aircraft |
| Special rates | Gold, silver and jewellery at 3%. Rough precious and semi-precious stones have a separate, lower rate |
Reverse charge, briefly
Normally the supplier collects GST and pays it to the government. Under reverse charge, the buyer pays the GST instead. It applies only to goods and services the government has notified for reverse charge.
The calculation does not change (amount × rate). What changes is who pays, and the supplier's invoice must say that tax is payable on reverse charge. As the buyer, you pay this tax in cash and can usually claim it back as input tax credit if you use the purchase for your business.
From calculator to GST invoice
A calculator is fine for a quick check. On an invoice, the tax has to be worked out line by line with HSN codes and shown under the right head. JustBill does this on every line. It compares your state with your customer's to choose CGST and SGST or IGST, handles prices entered with or without GST, and rounds off the total.
See the GST invoice format for the fields a tax invoice needs, or read about our GST billing software.
Frequently asked questions
How do I calculate GST from the total amount?
Divide the total by (1 + rate ÷ 100) to get the taxable value, then subtract it from the total to get the GST. For ₹1,180 at 18%: 1,180 ÷ 1.18 = ₹1,000 taxable value, so GST is ₹180.
What is the formula to add GST to a price?
GST = price × rate ÷ 100, and the total is price + GST. For ₹5,000 at 18%, GST is ₹900 and the total is ₹5,900.
What is a reverse GST calculator?
It works backwards from a price that already includes GST to find the taxable value and the tax inside it. It is the same as an inclusive GST calculator. Choose "remove GST" in the calculator above.
How is GST split between CGST and SGST?
Equally. On an intra-state sale at 18%, you charge 9% CGST and 9% SGST. On an inter-state sale, you charge the full 18% as IGST.
What are the current GST rates in India?
Since 22 September 2025, the main rates are 5% and 18%, with a 40% special rate for specified sin and luxury goods and services. Some items are nil-rated, and a few goods like gold and jewellery have special low rates. Always check the rate for your HSN or SAC code.
Are the 12% and 28% GST rates still used?
No, they were removed in the rate rationalisation that took effect on 22 September 2025. Most items that were at 12% moved to 5%, most at 28% moved to 18%, and some moved to 40%. Check the current rate for your specific HSN or SAC.
Last updated:
Keep reading
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