GST Calculator
TaxCalculate GST on any amount instantly. Supports 5%, 12%, 18%, and 28% GST slabs. Shows CGST, SGST breakdown and total inclusive price.
GST Amount
What is a GST?
The GST Calculator instantly computes the Goods and Services Tax on any base amount — displaying the total GST, the CGST and SGST components, and the GST-inclusive final price. Whether you are raising a client invoice, pricing a product for retail, or checking whether a supplier bill is correctly taxed, this tool delivers the exact figures required under India's GST framework without any manual arithmetic.
GST (Goods and Services Tax) is India's comprehensive indirect tax, introduced on 1 July 2017 to replace a fragmented system of over a dozen central and state levies — including VAT, Service Tax, Central Excise Duty, Entry Tax, and Octroi. The reform unified the country into a single tax market, removed inter-state tax barriers, and sharply reduced compliance overhead for businesses of all sizes.
India uses a dual GST structure: the Central Government collects CGST (Central GST) and the State Government collects SGST (State GST), each at exactly half the applicable rate. For inter-state transactions, IGST (Integrated GST) replaces both and applies at the full rate, with revenues shared between the Centre and the destination state.
GST is levied at four distinct rate slabs, each matched to the nature of the goods or services:
- 5% — essential commodities: unpackaged food items, medicines, public transport fares, newspapers
- 12% — standard goods: processed foods, business equipment, some textiles and apparel
- 18% — most goods and services: electronics, mobile phones, restaurants, telecom, IT and software services, professional consulting
- 28% — luxury and demerit goods: automobiles, tobacco products, aerated beverages, premium appliances
A nil (0%) rate covers staples like fresh vegetables, milk, eggs, and printed educational material. Petroleum products, alcohol for human consumption, and electricity currently sit outside the GST framework entirely and are taxed by states under separate legislation.
The backbone of the GST system is the Input Tax Credit (ITC) mechanism — GST-registered businesses offset the tax paid on inputs against the GST they owe on their outputs. This eliminates the cascading tax-on-tax effect that existed under the old VAT regime, ensuring the final GST burden falls entirely on the end consumer rather than compounding at each stage of production and distribution.
How to use this GST calculator
Enter the Amount (Exclusive of GST) — this is the base price of your goods or services before any tax is added. For an invoice you are raising, this is your fee or product price. If you already have a GST-inclusive figure (such as an MRP), divide it by (1 + GST Rate ÷ 100) first to arrive at the base — for example, ₹1,18,000 at 18% yields a base of ₹1,00,000.
Select the GST Rate — choose the slab applicable to your goods or service: 5% for essential goods, 12% for standard goods, 18% for most services and manufactured goods, or 28% for luxury and demerit goods. If you are unsure of the correct slab, look up the HSN code (Harmonised System Nomenclature, for goods) or SAC code (Services Accounting Code, for services) in the GST Council's official rate schedule.
Read the GST Amount — the highlighted output shows the total tax to be charged. This is the amount you collect from your buyer and — net of eligible input tax credits — remit to the government via your monthly or quarterly GST return.
Note the CGST and SGST split — for intra-state invoices, both figures must appear as separate line items on your tax invoice. Each is exactly half the total GST. If your transaction is inter-state, neither CGST nor SGST applies — only IGST at the full combined rate.
Use Total (incl. GST) as your invoice total — this is the bottom-line amount your client pays. Print this as the invoice total and include base price, CGST, and SGST as supporting line items above it to produce a GST-compliant invoice format.
Formula & Methodology
GST on a base (exclusive) price:
GST Amount = Base Amount × (GST Rate ÷ 100)
Total (incl. GST) = Base Amount + GST Amount
= Base Amount × (1 + GST Rate ÷ 100)
CGST = SGST = GST Amount ÷ 2
Reverse GST (extracting base and tax from a GST-inclusive price):
Base Amount = Inclusive Price ÷ (1 + GST Rate ÷ 100)
GST Amount = Inclusive Price − Base Amount
Variable definitions:
- Base Amount — the pre-tax value of goods or services (the amount you enter)
- GST Rate — the applicable slab: 5%, 12%, 18%, or 28%
- GST Amount — total tax levied on the transaction (sum of CGST and SGST)
- CGST — Central Government's portion, always ½ × GST Amount
- SGST / UTGST — State or Union Territory Government's portion, always ½ × GST Amount
- Total Amount — the GST-inclusive price paid by the buyer
Assumptions:
- An intra-state transaction is assumed. For inter-state supplies, only IGST applies at the full combined rate — this calculator does not model IGST separately.
- GST is applied as simple addition on the base amount. The 28% slab GST cess (applicable on certain goods like tobacco and aerated drinks) is not modelled here.
- No compound tax layers are included — each calculation is a single-stage computation.
Worked example 1 — freelance services at 18%:
A UI/UX designer raises an invoice for ₹60,000 worth of design services (18% GST slab):
- GST Amount = ₹60,000 × 0.18 = ₹10,800
- CGST = ₹5,400 | SGST = ₹5,400
- Invoice total = ₹60,000 + ₹10,800 = ₹70,800
The client pays ₹70,800. If the client is GST-registered, they may claim ₹10,800 as input tax credit against their own output tax liability, effectively reducing their net cost to ₹60,000.
Worked example 2 — retail goods at 28%:
A retailer sells a premium smartwatch with a base price of ₹25,000 (28% slab):
- GST Amount = ₹25,000 × 0.28 = ₹7,000
- CGST = ₹3,500 | SGST = ₹3,500
- MRP-equivalent price = ₹25,000 + ₹7,000 = ₹32,000
An end consumer purchasing this watch pays ₹32,000 with no ITC benefit — the full ₹7,000 GST is the final tax cost for a non-registered buyer.