What is the GST Calculator?
The GST Calculator works out Goods and Services Tax on any amount in seconds. Enter the price, choose the GST rate and tell the tool whether the figure is exclusive (GST to be added) or inclusive (GST already built in). It instantly shows the taxable value, the total GST and the split into CGST and SGST for intra-state supplies or IGST for inter-state supplies, along with an invoice-style break-up table and the amount in words.
GST rates after the September 2025 rationalisation
From 22 September 2025 India moved to a simpler two-slab structure: a 5% merit rate for essentials such as packaged food, medicines, soaps and footwear, and an 18% standard rate for most other goods and services including cement, air-conditioners, televisions and small cars. A 40% special rate applies to sin and luxury items such as pan masala, aerated drinks, large cars and motorcycles above 350 cc. Special rates of 0.25%, 1.5% and 3% continue for diamonds, precious stones and gold. The old 12% and 28% slabs survive only for a handful of transitional items, so the calculator still lists them.
Formula used
- Exclusive: GST = Amount × Rate ÷ 100; Invoice total = Amount + GST
- Inclusive: Taxable value = Amount × 100 ÷ (100 + Rate); GST = Amount − Taxable value
- Intra-state: CGST = SGST = GST ÷ 2. Inter-state: IGST = full GST
Worked example
A Jaipur trader sells goods worth ₹10,000 (exclusive) at 18% to a buyer in Rajasthan. GST = 10,000 × 18 ÷ 100 = ₹1,800, split as CGST ₹900 and SGST ₹900. Invoice total = ₹11,800. If the same goods were sold to Delhi, IGST of ₹1,800 would apply instead. Had the customer paid an inclusive price of ₹11,800, the taxable value would be 11,800 × 100 ÷ 118 = ₹10,000.
Who should use it
Shopkeepers preparing bills, freelancers quoting fees, accountants checking vendor invoices, and consumers who want to see how much tax sits inside an MRP. The quantity field lets you price multiple units, and the cess field handles products like tobacco and aerated water that attract compensation cess on top of GST.
Frequently Asked Questions
How do I calculate 18% GST on an amount?
Multiply the amount by 0.18. For ₹5,000 the GST is ₹900, giving a total of ₹5,900. For intra-state sales this is CGST ₹450 + SGST ₹450.
How do I remove GST from an inclusive price?
Divide the inclusive price by (1 + rate/100). ₹1,180 at 18% → 1,180 ÷ 1.18 = ₹1,000 taxable value and ₹180 GST.
When is IGST charged instead of CGST and SGST?
IGST applies when the supplier and the place of supply are in different states or Union Territories, and on imports. Within the same state, GST is split equally into CGST and SGST/UTGST.
Which GST slabs exist now?
After the 56th GST Council decisions effective 22 September 2025, the main slabs are 5% and 18%, with 40% for sin/luxury goods and 0.25%/1.5%/3% for diamonds and bullion.
Disclaimer: This tool is for general information and estimation only. Tax rates and rules change — verify with official sources or a professional before acting. Read full disclaimer.