How to calculate GST
GST (Goods and Services Tax) is charged on most goods and services sold in India. Depending on whether your price already includes GST, use one of these formulas:
Remove GST: Base = Amount × 100 ÷ (100 + Rate) → GST = Amount − Base
Example: ₹1,000 + 18% GST = ₹1,180. Reverse: an MRP of ₹1,180 that includes 18% GST has a base price of ₹1,000 and GST of ₹180. A common mistake is to take 18% of 1,180 (= ₹212.40) – that is wrong, because GST is charged on the base, not on the total.
CGST, SGST and IGST
- Intra-state sale (seller and buyer in the same state): GST is split equally – half CGST (Centre) and half SGST/UTGST (State). 18% = 9% CGST + 9% SGST.
- Inter-state sale or import: the full GST is charged as IGST.
Current GST slabs
After the GST rate rationalisation effective 22 September 2025, the main slabs are 5% (essential and common-use goods) and 18% (standard rate), with 40% for specified luxury and sin goods, nil for many essentials, and special rates such as 3% for gold and 0.25% for rough diamonds. The old 12% and 28% slabs were removed for most items, but they are kept in the dropdown so you can check older invoices. The exact rate depends on the HSN/SAC code of the item – confirm it on the CBIC website or with your CA.
Who uses a GST calculator?
Shopkeepers making kachcha bills, freelancers raising invoices, online sellers fixing their selling price, and customers who want to know how much tax is inside the MRP. Dukaan ke liye tip: agar aap composition scheme mein hain to customer se GST collect nahi kar sakte – aapko turnover par fixed rate dena hota hai. This tool is for quick calculation only and is not legal or tax advice.
Frequently asked questions (FAQ)
How do I remove 18% GST from a price?
Divide the price by 1.18. For ₹1,180, base price = 1,180 ÷ 1.18 = ₹1,000 and GST = ₹180.
What are the GST slabs now?
Since 22 September 2025 the main GST slabs are 5% and 18%, with 40% for specified luxury/sin goods, nil for many essentials, and special rates like 3% for gold.
CGST aur SGST kitna hota hai?
Same state ke andar sale par GST aadha-aadha bant jata hai. 18% GST = 9% CGST + 9% SGST.
When is IGST charged?
IGST is charged on inter-state supplies and imports, at the full GST rate.
Is GST charged on MRP?
MRP already includes all taxes. To find the GST inside an MRP, use the 'Remove GST' option.