GST Calculator

GST (Goods and Services Tax) is a value-added tax levied on the supply of goods and services in India. It is calculated as a percentage of the taxable value (base price). The formula is: GST Amount = Base Price × (GST Rate / 100). The total amount payable = Base Price + GST Amount. For example, at 18% GST on a base price of ₹1,000, the GST is ₹180 and the total is ₹1,180.

India has four primary GST slab rates: 5% applies to essential items such as packaged food items and footwear below ₹1,000; 12% applies to standard items like processed food, computers, and mobile phones; 18% covers most goods and services including telecom services, IT services, and restaurant bills; 28% applies to luxury and sin goods like cars, tobacco products, premium appliances, and aerated drinks. Essential items like fresh vegetables, milk, and eggs are exempt from GST.

CGST (Central GST) and SGST (State GST) are levied together on intra-state transactions, when goods or services are supplied within the same state. The total GST is split equally: half collected as CGST by the central government and half as SGST by the state government. IGST (Integrated GST) is levied on inter-state transactions, when goods or services cross state borders. The full GST amount is collected as IGST by the central government and later apportioned to the destination state.

Input Tax Credit lets a registered business reduce the GST it owes on sales by the GST it already paid on purchases used for the business, so tax is only paid on the value actually added at each stage. This is the mechanism that stops GST from cascading (tax being charged on top of tax) as goods move through the supply chain.

Under reverse charge, the buyer pays GST directly to the government instead of the supplier, reversing the usual flow. This applies to specific notified categories of goods and services, such as certain imports of services and supplies from goods transport agencies, rather than to transactions generally.

HSN (Harmonised System of Nomenclature) code is a standardised numeric code used to classify goods for tax purposes, and it determines which GST slab rate applies to a given product. GST invoices are required to mention the HSN code, with the number of digits required depending on the business's annual turnover.

To extract GST from a GST-inclusive total, use: Base Price = Total Amount / (1 + GST Rate / 100). Then GST Amount = Total Amount - Base Price. For example, if you paid ₹1,180 for an item at 18% GST, the base price is ₹1,180 / 1.18 = ₹1,000 and the GST component is ₹180.

To add GST to a base price, multiply: Total Amount = Base Price × (1 + GST Rate / 100). For a base price of ₹1,000 at 12% GST, the total is ₹1,000 × 1.12 = ₹1,120, with ₹120 being the GST amount.

The standard GST formulas are: (1) GST Amount = Base Price × (GST Rate / 100). (2) GST-inclusive Total = Base Price × (1 + GST Rate / 100). (3) Base Price from inclusive amount = Total Amount / (1 + GST Rate / 100). (4) For intra-state: CGST = SGST = GST Amount / 2. For inter-state: IGST = GST Amount.

Yes, GST rates are uniform across all states under India's unified tax system. The total tax percentage for any given product or service is the same nationwide. The only difference is how the tax is split: intra-state transactions use CGST + SGST (50-50 split), while inter-state transactions use IGST (full amount collected by the centre). The effective tax burden is identical in both cases.

GST registration is mandatory for businesses with aggregate turnover exceeding ₹40 lakh (₹20 lakh for special category states) in a financial year. Registration is also required for businesses engaged in inter-state supply, e-commerce operators, casual taxable persons, and those required to pay tax under reverse charge. Businesses supplying through e-commerce platforms must register regardless of turnover.

No. A few items are kept entirely outside GST and continue under the earlier tax system, most notably petrol, diesel, aviation turbine fuel, natural gas, and alcohol for human consumption, which attract state excise duty and VAT instead. Everything else falls under GST, either at one of the four slab rates or as an exempt item.

Late payment attracts interest at 18% per annum on the outstanding tax amount, calculated from the day after the due date until payment. A separate, smaller per-day late fee also applies for filing the return itself late, with a lower rate for a nil return, subject to a maximum cap.

No. Input Tax Credit is available only to GST-registered businesses, and only for purchases used in the course of business. An individual buying goods or services for personal use pays GST as a final consumer and cannot claim any of it back.

The GST Council decides tax rates, exemptions, and rule changes. It is a constitutional body chaired by the Union Finance Minister, with the finance ministers of every state and union territory as members, so rate changes require agreement between the central and state governments rather than a unilateral decision.

GSTIN (Goods and Services Tax Identification Number) is a 15-character alphanumeric code assigned to every GST-registered business. It is built from the two-digit state code, the business PAN, a registration count digit for that state, a default character, and a final checksum digit, so it uniquely identifies both the business and the state it is registered in.

VAT was levied separately by each state at different rates, and tax paid at one stage often could not be fully offset against tax at the next, creating a cascading tax-on-tax effect. GST replaced this with one uniform nationwide tax structure and seamless input tax credit across the entire supply chain, so businesses are only ever taxed on the value they actually add.

A freelancer or consultant providing services must register for GST once their aggregate turnover crosses ₹20 lakh in a financial year (₹10 lakh in special category states), a lower threshold than the one that applies to businesses selling goods. Once registered, GST must be charged and collected on invoices for services rendered.

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