Prepared by: FreeBytes Editorial Team · Reviewed by: FreeBytes Research Team
Methodology: We cross-check formulas, slabs, and examples against published government, regulator, lender, and scheme documentation before updating the page.
Calculations use the latest available Indian tax slabs, interest rates, and government rules. This tool is for informational purposes only and does not constitute financial or tax advice. Consult a qualified Chartered Accountant or financial advisor for decisions specific to your situation.
GST Calculator
Calculate Goods and Services Tax (GST) for India including CGST, SGST, and IGST components.
How to Use the GST Calculator?
Enter the amount and GST rate to calculate tax components for your business transactions.
What is GST?
Goods and Services Tax (GST) is an indirect tax levied in India. It has replaced multiple taxes like VAT, Service Tax, etc. GST components include:
- CGST: Central Goods and Services Tax (collected by Central Government)
- SGST: State Goods and Services Tax (collected by State Government)
- IGST: Integrated Goods and Services Tax (for inter-state transactions)
- UTGST: Union Territory Goods and Services Tax
GST Rate Structure
- 0%: Essential items like food grains, fresh fruits, vegetables
- 5%: Daily necessities like sugar, tea, coffee, spices
- 12%: Items like computers, processed foods
- 18%: Most goods and services fall under this category
- 28%: Luxury items like cars, tobacco, aerated drinks
GST Calculation Types
- GST Exclusive: GST is added to the base price
- GST Inclusive: GST is included in the total price (extracted from total)
- Intra-state: CGST + SGST (within same state)
- Inter-state: IGST (between different states)
How to Calculate GST (Formulas + Examples)
There are two situations you will encounter, and each uses a different formula:
1. Adding GST to a base price (GST exclusive): GST Amount = Base Price × (GST Rate ÷ 100), and Total = Base Price + GST Amount. For example, on a product priced at ₹10,000 with 18% GST: GST = 10,000 × 0.18 = ₹1,800, so the customer pays ₹11,800. For an intra-state sale this ₹1,800 splits equally into ₹900 CGST and ₹900 SGST.
2. Extracting GST from a total price (GST inclusive): Base Price = Total ÷ (1 + GST Rate ÷ 100), and GST Amount = Total − Base Price. For example, if an invoice total is ₹11,800 inclusive of 18% GST: Base Price = 11,800 ÷ 1.18 = ₹10,000, so the embedded GST is ₹1,800. This reverse calculation is essential when a displayed price already includes tax and you need to record the taxable value separately.
When CGST + SGST Applies vs IGST
The split depends on where the supplier and the customer are located. For an intra-state transaction (both in the same state), the total GST is divided equally between CGST (central) and SGST (state) — an 18% rate becomes 9% CGST + 9% SGST. For an inter-state transaction (different states, or imports), the full rate is charged as a single IGST, which the central government later apportions to the destination state. The customer pays the same total either way; only the internal accounting differs.
Who Needs to Register for GST
GST registration is mandatory for businesses whose annual turnover exceeds ₹40 lakh for goods (₹20 lakh in special-category states) or ₹20 lakh for services (₹10 lakh in special-category states). Registration is also required for inter-state suppliers, e-commerce operators, and businesses under the reverse-charge mechanism, regardless of turnover. Registered businesses can claim Input Tax Credit — the GST they paid on purchases can be offset against the GST they collect on sales, so tax is effectively paid only on the value they add.
Common GST Calculation Mistakes to Avoid
- Applying the exclusive formula to an inclusive price: This overstates the tax. Always confirm whether a price already contains GST before calculating.
- Forgetting to split CGST and SGST: On intra-state invoices the two must be shown separately, each at half the total rate.
- Using the wrong slab: Verify the HSN/SAC code of the product or service to apply the correct 0%, 5%, 12%, 18%, or 28% rate.
- Ignoring rounding rules: GST should be rounded to the nearest rupee on the total invoice value as per CGST rules.
Frequently Asked Questions — GST Calculator
GST (Goods and Services Tax) is a unified indirect tax levied on the supply of goods and services across India. Introduced in July 2017, it replaced a complex web of central and state taxes including VAT, service tax, and excise duty, creating a single national market.
GST has five rate slabs: 0% on essential items (vegetables, milk, cereals), 5% on basic necessities (packaged food, medicines), 12% on processed goods and some services, 18% on most goods and services (the most common slab), and 28% on luxury items like cars, tobacco, and aerated drinks.
For intra-state transactions (seller and buyer in the same state), tax is split equally into CGST (Central GST) and SGST (State GST). For inter-state transactions (different states), only IGST (Integrated GST) is charged — it is collected by the Centre and later shared with the destination state.
In GST-exclusive mode, GST is added on top of the base price (e.g., ₹100 base + 18% GST = ₹118 total). In GST-inclusive mode, the quoted price already includes GST, and this calculator extracts the GST component from the total (e.g., ₹118 total → ₹100 base + ₹18 GST).
Businesses with annual turnover exceeding ₹40 lakh (goods) or ₹20 lakh (services) must register. The threshold is ₹10 lakh for businesses in special category states (e.g., Manipur, Mizoram, Nagaland, Tripura). E-commerce sellers and inter-state suppliers must register regardless of turnover.
Yes. Registered GST taxpayers can claim ITC for GST paid on business purchases and inputs. This ITC is offset against GST collected on sales, reducing the net tax payable. ITC is not available for personal expenses, motor vehicles (with exceptions), food, and certain other items.