How to calculate GST
GST (goods and services tax) is charged as a percentage of the taxable value, the price before GST. This calculator is for India’s GST.
Example: a laptop bag is priced at ₹1,000 before GST, and the rate is 18%. GST is 1,000 × 0.18 = ₹180, so the customer pays ₹1,180.
The calculator uses exact decimal arithmetic and rounds each tax amount half up to the nearest paisa. On a tax invoice, CGST and SGST are worked out separately on the taxable value, so the calculator does the same.
How to remove GST from an inclusive price
If a price already includes GST (for example an MRP), divide by 1 plus the rate to find the taxable value.
Example: a phone cover sells for ₹1,180 including 18% GST. The taxable value is 1,180 ÷ 1.18 = ₹1,000, and the GST is ₹180. Within a state, that is ₹90 CGST + ₹90 SGST.
Do not take 18% off the inclusive price. 1,180 × 0.82 = ₹967.60, which is wrong, because the 18% was charged on the smaller taxable value.
CGST, SGST, UTGST and IGST
Which tax heads appear on the invoice depends on where the supplier is and where the supply goes.
| Type of supply | Taxes charged | Split at 18% |
|---|---|---|
| Within the same state | CGST + SGST | 9% + 9% |
| Within a Union Territory without a legislature | CGST + UTGST | 9% + 9% |
| From one state to another | IGST | 18% |
| Imports | IGST (plus customs duty) | 18% |
The total GST is the same either way; only the split changes. CGST goes to the central government and SGST or UTGST to the state or UT. IGST is collected by the centre and shared with the destination state.
Example (inter-state): a Pune business sells goods worth ₹50,000 at 5% to a buyer in Bengaluru. IGST is 50,000 × 0.05 = ₹2,500, and the invoice total is ₹52,500. If the buyer were in Mumbai, the same ₹2,500 would appear as ₹1,250 CGST and ₹1,250 SGST.
GST rates after the 2025 reform
On 3 September 2025, the 56th meeting of the GST Council agreed to simplify the rate structure. From 22 September 2025, most goods and services moved to two main rates:
- 5% for most essentials, packaged foods, medicines and many daily-use items.
- 18% as the standard rate for most other goods and services, including many items that used to be taxed at 28%, such as small cars, air conditioners and cement.
- 40% as a special rate for a short list of luxury and “sin” goods and services, such as pan masala, tobacco products, aerated sugary drinks, large cars, and betting and online gaming.
Some items stay exempt (nil), such as fresh food, milk and individual life and health insurance. Specific rates of 3% for gold, silver and jewellery and 0.25% for rough precious stones continue.
Tobacco products kept the old 28% rate plus compensation cess for a few months. From 1 February 2026 the compensation cess ended, and these products moved to the 40% GST rate, with a separate excise duty or health cess outside GST. Older 12% and 28% rates may still appear on invoices dated before these changes.
Tips
- Check the HSN or SAC code. The rate depends on the exact classification of the item or service, and some items have conditions. The calculator does not look up rates for specific products.
- MRP includes GST. Retail prices printed on packs in India are GST-inclusive, so use Remove GST to find the taxable value.
- Input tax credit lets a registered business reduce its GST bill by the GST it paid on purchases. This calculator shows the tax on one sale only.
- Rounding: GST law lets tax amounts be rounded to the nearest rupee on returns. Invoices often show paise, as here.
This tool does the arithmetic only and is not tax advice. For registration, returns or a ruling on a specific item, check the CBIC GST portal or ask a chartered accountant.
Related calculators
To estimate your income tax under the new and old regimes, use the India income tax calculator. If you buy on instalments, the EMI calculator shows the monthly payment. For VAT in the UK, EU, UAE or Saudi Arabia, try the VAT calculator.