The GST Calculator does the two calculations businesses and shoppers need most. It adds GST to a net (exclusive) price, and it removes GST from an inclusive price (MRP or invoice total) to find the base value and tax. It also splits the tax into CGST and SGST for sales within a state, or shows the full amount as IGST for sales between states.
How to use the GST calculator
- Choose Add GST if your amount is before tax, or Remove GST if it already includes tax.
- Enter the amount.
- Pick the GST rate that applies to the goods or service.
- Press Calculate GST to see the base amount, total GST, CGST/SGST split and total.
GST formulas
Adding GST (exclusive → inclusive)
Total price = Net price + GST amount
Example: a service billed at ₹1,000 + 18% GST. GST = ₹180, so the invoice total is ₹1,180.
Removing GST (inclusive → exclusive)
GST amount = Inclusive price − Base price
Example: an item with an MRP of ₹2,360 including 18% GST. Base = 2,360 × 100 ÷ 118 = ₹2,000 and GST = ₹360.
CGST, SGST and IGST
| Type of sale | Tax charged | Example at 18% on ₹10,000 |
|---|---|---|
| Within the same state (intra-state) | CGST + SGST, half each | CGST ₹900 + SGST ₹900 |
| Within a Union Territory without a legislature | CGST + UTGST | CGST ₹900 + UTGST ₹900 |
| Between states, imports or exports (inter-state) | IGST, full rate | IGST ₹1,800 |
The total tax is the same in every case. Only the government that receives it changes. The place of supply rules decide which applies.
GST rate structure after September 2025
| Rate | Applies to (broad examples) |
|---|---|
| 0% / exempt | Fresh fruit and vegetables, milk, unbranded cereals, education, healthcare services, individual life and health insurance premiums |
| 0.25% / 3% | Rough diamonds (0.25%); gold, silver and jewellery (3%) |
| 5% | Many daily-use packaged foods, toiletries such as soap and toothpaste, medicines, fertilisers, most restaurant services (without input tax credit) |
| 18% | Most goods and services: electronics, ACs and TVs, small cars, cement, telecom, banking and professional services |
| 40% | Luxury and sin goods: pan masala, aerated and sugary drinks, larger luxury cars, and similar items |
This list is a simplified summary. Rates depend on the exact HSN/SAC code and conditions. Check the latest rate notifications on the CBIC GST portal before invoicing.
Worked business example
A Pune-based designer bills a Mumbai client ₹50,000 for services at 18% (both in Maharashtra, so intra-state):
- CGST 9% = ₹4,500
- SGST 9% = ₹4,500
- Invoice total = ₹59,000
The same invoice to a client in Bengaluru (inter-state) would show IGST 18% = ₹9,000, with the same total of ₹59,000.
Input tax credit in one paragraph
A registered business pays GST on its purchases (input tax) and collects GST on its sales (output tax). It deposits only the difference with the government. If you paid ₹1,800 GST on materials and charged ₹3,600 GST on the finished product, you pay ₹1,800 net. That is why GST is called a tax on value added. Final consumers cannot claim input tax credit, so for them GST is a real cost.
Who needs to register for GST?
- Suppliers of goods with annual turnover above ₹40 lakh (₹20 lakh in some special-category states).
- Service providers with turnover above ₹20 lakh (₹10 lakh in some special-category states).
- Anyone making inter-state taxable supplies of goods, e-commerce sellers and some others, whatever their turnover. Small service providers have some exemptions.
Frequently asked questions
How do I calculate GST on an amount?
Multiply the net amount by the GST rate and divide by 100. At 18%, GST on ₹1,000 is ₹180, so the total is ₹1,180.
How do I remove GST from an inclusive price?
Divide the inclusive price by (1 + rate/100). For ₹1,180 at 18%, base = 1,180 ÷ 1.18 = ₹1,000, and the GST is ₹180. Do not subtract 18% of the inclusive amount.
What are the GST rates in India now?
Since 22 September 2025, the main rates are 5% and 18%, with 40% for luxury and sin goods. Gold is taxed at 3%, rough diamonds at 0.25%, and many essentials are exempt.
What is the difference between CGST, SGST and IGST?
For a sale within one state, GST is split equally into CGST (central) and SGST (state). For a sale between states, the full rate is charged as IGST. The total tax is the same either way.
Is GST charged on MRP?
MRP already includes all taxes, GST included. Shops cannot add GST on top of the printed MRP. To find the GST inside an MRP, use the Remove GST option.