GST (Goods and Services Tax) is India’s unified indirect tax on the supply of goods and services. To add GST, use GST = Base × Rate ÷ 100 and Total = Base + GST. To remove GST from an inclusive price, use Base = Inclusive ÷ (1 + Rate ÷ 100). Within a state the GST splits equally into CGST + SGST; across states it becomes IGST. This calculator does all three modes in real time and adds CGST/SGST/IGST splits, cess, bulk processing, invoices, profit, ITC and projections.
Key Takeaways
- GST (Goods and Services Tax) is India’s unified indirect tax on the supply of goods and services, in force since 1 July 2017.
- To add GST: GST = Base × Rate ÷ 100. To remove GST: Base = Inclusive ÷ (1 + Rate ÷ 100).
- Intra-state supplies split GST equally into CGST + SGST; inter-state supplies and imports use a single IGST.
- Standard slabs are 0%, 5%, 12%, 18% and 28%, with special 0.25% and 3% rates and a cess on luxury/sin goods.
- 18% is the standard rate covering most goods and services; essentials are nil or 5%, luxuries are 28%.
- Input Tax Credit lets registered businesses offset GST paid on purchases against GST collected on sales.
- Registration is mandatory above ₹40 lakh (goods) / ₹20 lakh (services) turnover, and for inter-state and e-commerce sellers.
- Exports are zero-rated — no GST is charged and accumulated input credit is refundable.
- This calculator adds, removes and reverse-calculates GST, splits CGST/SGST/IGST, handles cess, bulk items and invoices — entirely in your browser.
People Also Ask
How do I calculate 18% GST on ₹1,000?
18% of ₹1,000 is ₹180, so the GST-inclusive total is ₹1,180. For an intra-state sale this is ₹90 CGST + ₹90 SGST.
How do I remove 18% GST from ₹1,180?
Divide by 1.18: ₹1,180 ÷ 1.18 = ₹1,000 base, with ₹180 as the GST component.
Is GST split into CGST and SGST?
Yes, for supplies within the same state. The total GST is divided equally — 18% becomes 9% CGST + 9% SGST. Inter-state supplies use IGST instead.
What is the standard GST rate in India?
18% is the standard rate and applies to most goods and services. The other slabs are 0%, 5%, 12% and 28%.
Who has to register for GST?
Businesses above ₹40 lakh turnover for goods (₹20 lakh for services), and all inter-state suppliers and e-commerce sellers regardless of turnover.
Can I claim back the GST I pay?
If you are a GST-registered business, yes — GST paid on business purchases is claimable as Input Tax Credit against the GST you collect on sales.
How is GST calculated on MRP?
MRP includes GST. To find the pre-tax price, divide the MRP by (1 + rate ÷ 100). At 18%, an MRP of ₹1,180 has a base of ₹1,000.
Are exports charged GST?
No. Exports are zero-rated — you charge no GST and can claim a refund of the input credit accumulated on related purchases.
What Is GST?
GST — the Goods and Services Tax — is a single, comprehensive, destination-based indirect tax levied on the supply of goods and services across India. Rolled out on 1 July 2017 under the slogan “One Nation, One Tax”, it replaced a tangled web of central and state levies — excise duty, service tax, VAT, CST, octroi, entry tax and a dozen cesses — with one unified tax administered jointly by the Centre and the states through the GST Council.
The defining feature of GST is that it is a value-added tax: it is charged at every stage of the supply chain, but each business in the chain gets credit for the tax already paid on its purchases. The end consumer ultimately bears the tax, while businesses act as collection agents. This design removes the old “tax-on-tax” cascade, widens the tax base, and creates a seamless national market where goods and services move across state borders without a thicket of separate state taxes.
GST Full Form and Meaning
GST stands for Goods and Services Tax. The name captures its scope precisely: unlike the older system that taxed goods and services under different laws and authorities, GST brings both under a single umbrella. Whether you sell a physical product, provide a professional service, license software or run a restaurant, the same framework, the same return formats and the same credit mechanism apply.
In essence, GST is an indirect tax — meaning it is collected by businesses from customers and passed on to the government, rather than being paid directly out of personal income. It is “value-added” because tax is effectively levied only on the value each business adds, and “destination-based” because the revenue accrues to the state where the goods or services are finally consumed, not where they are produced.
How GST Works
Imagine a product that travels from manufacturer to wholesaler to retailer to you. At each handover, the seller adds GST to the price and issues a tax invoice. Crucially, each buyer in the chain claims Input Tax Credit for the GST shown on that invoice, so the tax they actually remit to the government is only on the value they themselves added. By the time the product reaches the consumer, the total GST collected equals exactly the rate applied to the final retail price — no more, no less.
This credit chain is what makes GST efficient and self-policing. A buyer can only claim credit if the supplier has reported and paid the tax, which encourages compliance throughout the network. The calculator on this page mirrors that logic: it shows you the tax at a single transaction level, lets you net output tax against input credit in the Profit and ITC tools, and projects your monthly and annual liability in the dashboard.
GST Structure in India
India runs a unique dual-GST model that reflects its federal structure. Every intra-state transaction attracts two parallel components — Central GST (CGST) and State GST (SGST) — levied simultaneously on the same value and split equally. Inter-state transactions and imports instead attract a single Integrated GST (IGST). A separate UTGST applies in union territories without a legislature, mirroring SGST.
Sitting above this is the GST Council, a constitutional body chaired by the Union Finance Minister with state finance ministers as members, which decides rates, exemptions, thresholds and procedural rules by consensus. This cooperative federalism is why a tablet attracts the same GST in Mumbai as in Chennai, even though the revenue is shared differently. The structure balances a unified national tax with the states’ fiscal autonomy.
CGST Explained
CGST, the Central Goods and Services Tax, is the share of GST on an intra-state supply that flows to the Central Government. It is governed by the CGST Act, 2017. On any sale within a single state, the headline GST rate is divided in half — the CGST portion and an equal SGST portion. So an 18% intra-state supply carries 9% CGST and 9% SGST.
Because CGST and SGST are charged on the same taxable value and at equal rates, the buyer’s total tax is unchanged whether you express it as one number or two. The split matters for revenue allocation and for Input Tax Credit rules: CGST credit can be set off against CGST and then IGST liability, but not directly against SGST, and vice versa. This calculator automatically performs the 50:50 split whenever you select an intra-state supply.
SGST Explained
SGST, the State Goods and Services Tax, is the counterpart to CGST: it is the half of an intra-state GST that goes to the State Government where the supply takes place, under each state’s SGST Act. Together, CGST and SGST ensure that both the Centre and the consuming state earn from the same transaction without double taxation, because the rate is simply shared.
For union territories without their own legislature — such as Chandigarh or the Andaman and Nicobar Islands — UTGST takes the place of SGST and behaves identically. When you toggle the supply type to intra-state in this tool, the SGST figure shown is exactly what you would record in the SGST column of a compliant tax invoice.
IGST Explained
IGST, the Integrated Goods and Services Tax, applies whenever a supply crosses state lines or enters the country as an import. Instead of splitting the tax, IGST levies the entire rate as a single integrated tax collected by the Central Government, which then transfers the destination state’s share to it through a clearing mechanism. An 18% inter-state supply therefore carries 18% IGST and zero CGST/SGST.
IGST is the engine that makes the national market seamless: a seller in Karnataka shipping to a buyer in Delhi charges one IGST instead of grappling with two states’ taxes, and the buyer claims the full IGST as credit. IGST credit is the most flexible — it can be used against IGST, CGST and SGST liabilities in that order. Select inter-state in the calculator to see the full amount routed to IGST.
GST Rates and Slabs Explained
India’s GST uses a multi-rate structure designed to keep essentials affordable while taxing luxuries more heavily. The principal slabs are 0% (nil-rated essentials like fresh produce, grains and salt), 5% (mass-consumption items and transport), 12% (processed foods, computers and mid-tier goods), 18% (the standard rate covering most goods and services), and 28% (luxury and “sin” goods). Two special rates of 0.25% and 3% apply to rough diamonds and to gold and precious metals respectively.
On top of the 28% slab, a compensation cess is levied on a narrow set of demerit and luxury products — cars, tobacco, pan masala and aerated drinks — at rates that vary by item. The right slab for any product depends on its HSN classification, so two similar-looking items can fall in different brackets. This calculator includes one-tap chips for every standard slab plus a custom field for cess and non-standard rates.
GST on Goods
For physical goods, the applicable GST rate is determined by the product’s HSN (Harmonised System of Nomenclature) code. Everyday essentials and unbranded staples are often nil-rated or taxed at 5%; packaged and processed goods, apparel above ₹1,000 and electronics like phones sit at 12% or 18%; and high-end consumer durables, automobiles and aerated drinks attract 28% plus possible cess.
The taxable value of goods is the transaction value — the actual price paid, net of any discount shown on the invoice, plus incidental charges like packing and freight where applicable. Because the rate hinges on correct classification, misclassifying a product can lead to short payment, interest and penalties, or to overcharging customers. Use the Product mode and the slab chips here to model the right rate before you price or invoice.
GST on Services
Services are classified under SAC (Services Accounting Code) and the standard rate for most of them is 18% — this covers consulting, freelancing, IT and software, agencies, telecom, banking and professional services. Lower rates apply to specific services: 5% on economy transport and standalone restaurants (without ITC), and 12% on certain works contracts and mid-range hotels, while premium hospitality and gaming sit at 28%.
For service providers, the place of supply rules are especially important because they decide whether you charge CGST + SGST or IGST, and whether a supply qualifies as an export. The Service mode in this calculator presets the common service rates, and the Profit tool helps freelancers and agencies see exactly how much of their invoice is tax, how much they can reclaim as ITC, and what lands in their pocket.
GST Registration Guide
Registration is mandatory once your aggregate annual turnover crosses ₹40 lakh for goods (₹20 lakh in special-category states) or ₹20 lakh for services (₹10 lakh in special-category states). It is also compulsory — irrespective of turnover — for inter-state suppliers, e-commerce sellers, casual and non-resident taxable persons, input service distributors and anyone liable under reverse charge.
The process is entirely online on the GST portal: you submit your PAN, business details, bank account and proof of address, complete Aadhaar authentication, and receive a 15-digit GSTIN, usually within a few working days. Many businesses below the threshold register voluntarily because it lets them claim Input Tax Credit and sell to larger, GST-registered customers who require tax invoices. Once registered, you must charge GST, file returns and maintain records even in months with no sales.
GST Filing Guide
GST compliance revolves around periodic returns filed on the GST portal. Most regular taxpayers file GSTR-1 (a detailed statement of outward supplies) and GSTR-3B (a summary return where tax is actually paid), either monthly or quarterly under the QRMP scheme for smaller taxpayers. The system auto-drafts GSTR-2B, a static statement of the ITC available to you based on your suppliers’ filings, which you reconcile before claiming credit.
Payment is made by first utilising the credit in your electronic credit ledger and paying any balance in cash. Late filing triggers a daily late fee and 18% annual interest on unpaid tax, and — importantly — can block your buyers from claiming their ITC, damaging relationships. Building a monthly routine of invoicing, reconciliation and filing, supported by tools like the dashboard here for forecasting liability, keeps compliance painless.
Understanding GST Returns
The GST return ecosystem has several forms tailored to taxpayer type. GSTR-1 reports sales invoice-by-invoice; GSTR-3B is the monthly/quarterly summary and payment return; GSTR-9 is the annual return for regular taxpayers above the turnover limit; and GSTR-9C is a reconciliation statement for larger entities. Composition dealers instead file CMP-08 quarterly and GSTR-4 annually.
These returns are interlinked: the data you file in GSTR-1 populates your customers’ GSTR-2B, and your GSTR-3B must reconcile with both your GSTR-1 and the ITC reflected in your GSTR-2B. Mismatches are the most common source of notices, so accurate, timely invoice reporting is the single best compliance habit. The figures this calculator produces — taxable value, CGST/SGST/IGST and net payable — map directly onto the fields in these returns.
Input Tax Credit (ITC)
Input Tax Credit is the mechanism that prevents tax cascading and is the heart of GST. When a registered business buys goods or services for its business, the GST it pays becomes a credit that can be set off against the GST it collects on its own sales. If you collect ₹18,000 in output tax and have ₹10,000 of eligible input credit, you remit only ₹8,000 in cash — the rest is settled through the credit ledger.
To claim ITC you need a valid tax invoice, you must have received the goods or services, the supplier must have paid the tax and filed their return so it appears in your GSTR-2B, and the purchase must not be a blocked credit under Section 17(5) (such as personal expenses, certain motor vehicles, or club memberships). The ITC tool on this page lets you total your input credits, apply any blocked or ineligible portion, and see your true net liability and cash savings.
GST for Freelancers
Freelancers — designers, developers, writers, consultants and creators — supply services, so the ₹20 lakh turnover threshold (₹10 lakh in special-category states) applies. Registration also becomes mandatory the moment you supply services to clients in another state or earn through certain online platforms, regardless of how small the income is. Most freelance services attract 18% GST.
The good news is that GST need not reduce your earnings: you charge it on top of your fee, and your clients (if registered) reclaim it as ITC, so it is a pass-through. You in turn can claim ITC on business expenses like a laptop, software subscriptions, internet and co-working space. For clients abroad, your services may qualify as zero-rated exports, letting you invoice without GST and claim refunds. Use the Service and Profit tools here to price your work correctly and see your real take-home.
GST for Small Businesses
For small businesses, GST is both a compliance obligation and a competitive tool. If your turnover is modest and your sales are local, you may stay below the threshold and skip registration — but you then cannot claim ITC or issue tax invoices, which can be a disadvantage when selling to registered buyers. Voluntary registration is common precisely to unlock these benefits.
Very small taxpayers can opt for the composition scheme, paying a low flat rate (1% for traders and manufacturers, 5% for restaurants, 6% for eligible service providers) on turnover with minimal paperwork, in exchange for giving up ITC and the ability to collect GST. Choosing between regular and composition registration depends on your margins, customer mix and input costs. The calculators here help you compare the tax impact of each path before you decide.
GST for E-commerce Sellers
Selling on marketplaces like Amazon, Flipkart or your own Shopify store brings specific GST rules. E-commerce sellers must register for GST regardless of turnover. Marketplaces collect TCS (Tax Collected at Source) at 1% (0.5% CGST + 0.5% SGST intra-state, or 1% IGST inter-state) on the net taxable value of your sales and deposit it against your GSTIN, where it reflects as a credit you can claim.
On the cost side, the commission, fulfilment, storage and advertising fees that platforms charge are services taxed at 18% GST — fully claimable as ITC by a registered seller, so they reduce your net liability rather than being a sunk cost. The eCommerce mode of this calculator models marketplace commission, the GST on that commission, and your net realisation per order, so you can see exactly what you keep after the platform and the tax department take their share.
GST for Startups
Startups should treat GST registration as part of incorporation hygiene. Early registration lets you accumulate Input Tax Credit on the heavy initial spend — equipment, software, professional fees and office setup — which you can carry forward and offset once revenue begins. It also signals legitimacy to enterprise customers and investors who expect compliant tax invoices.
For startups serving overseas customers, the export-of-services route is especially valuable: such supplies are zero-rated, so you invoice without GST and claim refunds of the GST embedded in your costs, improving cash flow. As you scale across states or onto e-commerce platforms, registration becomes mandatory anyway. Modelling your output tax, ITC and net liability early — as the dashboard and ITC tools here allow — helps you forecast working-capital needs accurately.
GST Compliance Guide
Good GST compliance rests on four habits: issue correct tax invoices for every supply, file accurate returns on time, reconcile your ITC against GSTR-2B each period, and keep your records for at least six years. Movement of goods above ₹50,000 needs an e-way bill, and adjustments to issued invoices are made through debit and credit notes rather than edits.
The cost of slipping is real — daily late fees, 18% interest on unpaid tax, blocked e-way bills, and ITC denial to your buyers that can sour commercial relationships. Conversely, clean compliance protects your credit chain and keeps refunds flowing. Treating GST as a monthly operating rhythm, rather than a year-end scramble, is the single biggest determinant of a stress-free experience, and the forecasting tools on this page are designed to support that rhythm.
GST Invoice Rules
A compliant GST tax invoice must carry specific particulars: the supplier’s name, address and GSTIN; a consecutive, unique invoice number and date; the recipient’s name, address and GSTIN (for B2B); the HSN or SAC code; a description, quantity and taxable value of each item; the GST rate and the amount of CGST, SGST/UTGST or IGST; the place of supply for inter-state sales; and whether tax is payable on reverse charge.
Invoices must be issued within prescribed time limits — at or before delivery for goods, and within 30 days of supply for services. A bill of supply is used instead when no tax is charged (composition dealers or exempt supplies). Getting the invoice right is not just procedural: it is the document on which your customer’s entire ITC claim depends. The Invoice Generator here produces a fully formatted, rule-compliant tax invoice you can download or print.
GST Calculation Formula
Adding GST to a GST-exclusive price is straightforward: GST Amount = (Original Cost × GST Rate) ÷ 100, and the Net (final) Price = Original Cost + GST Amount. For example, ₹10,000 at 18% gives ₹1,800 of GST and a ₹11,800 total, which for an intra-state supply splits into ₹900 CGST and ₹900 SGST.
Removing GST from a GST-inclusive price (reverse GST) uses: Base Amount = Inclusive Price ÷ (1 + GST Rate ÷ 100), and GST Amount = Inclusive Price − Base Amount. So ₹11,800 inclusive of 18% reduces to a ₹10,000 base and ₹1,800 of tax. When a compensation cess applies, it is added to the rate in the denominator for the reverse calculation. This calculator implements all three modes — add, remove and reverse — exactly to these formulas.
GST Calculation Examples
Example 1 — Adding GST: A retailer in Maharashtra sells furniture worth ₹50,000 to a customer in Maharashtra at 18%. GST = ₹9,000, split as ₹4,500 CGST + ₹4,500 SGST, so the invoice total is ₹59,000. Example 2 — Inter-state: the same sale to a customer in Gujarat carries ₹9,000 IGST instead, with the total still ₹59,000.
Example 3 — Removing GST: a shop quotes an all-inclusive price of ₹2,360 for an item at 18%. The base is ₹2,360 ÷ 1.18 = ₹2,000 and the GST is ₹360. Example 4 — With cess: a car priced at ₹10,00,000 at 28% GST plus 15% cess carries ₹2,80,000 GST and ₹1,50,000 cess, an effective tax of ₹4,30,000 (43%). Every one of these scenarios can be reproduced in seconds using the modes and inputs on this page.
Common GST Mistakes to Avoid
The most frequent errors are misclassifying products under the wrong HSN/SAC and therefore applying the wrong rate; charging CGST + SGST on an inter-state supply (or IGST on an intra-state one); forgetting to add or to back out cess on 28% items; and claiming Input Tax Credit on blocked categories or on invoices that do not appear in GSTR-2B. Each of these can trigger interest, penalties or denied credit.
Other common slips include issuing invoices without all mandatory fields, missing return due dates, failing to reconcile GSTR-3B with GSTR-1 and GSTR-2B, and mixing up inclusive and exclusive pricing so that the tax is computed on the wrong base. A reliable calculator that handles the split, the cess and the inclusive/exclusive logic for you — like this one — eliminates the arithmetic errors and lets you focus on classification and timely filing.
GST Best Practices
Adopt a few disciplines and GST becomes routine. Maintain a clean master of HSN/SAC codes and rates for everything you sell so classification is consistent. Always determine the place of supply first to pick the correct CGST/SGST or IGST treatment. Reconcile your purchase register with GSTR-2B every month before claiming ITC, and only deal with suppliers who file on time. Price using the right base — decide upfront whether your quoted prices are inclusive or exclusive of GST.
Automate where you can: generate compliant invoices, keep digital copies for the full retention period, and forecast your monthly and annual liability so cash is set aside for payment. Separate the GST you collect from your operating cash mentally — it is the government’s money you are holding. The toolkit on this page supports each of these practices, from accurate per-transaction tax to bulk processing, invoicing, ITC netting and forward projections.
Latest GST Updates and Trends
GST is a living system that the GST Council refines regularly — adjusting rates on specific goods and services, rationalising slabs, tightening ITC and invoice-matching rules, and expanding e-invoicing to progressively smaller businesses. Recent years have seen mandatory e-invoicing thresholds fall, stricter rules linking ITC to suppliers’ filings, and ongoing discussions about simplifying the rate structure.
Because rules and rates can change, always confirm the current rate and compliance requirement for your specific product or service against official notifications before filing or pricing. This calculator is kept aligned with the prevailing standard slabs and computation logic, but it is a planning and educational aid — for binding positions on classification, eligibility and procedure, consult a qualified GST practitioner or the official GST portal.
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Frequently Asked Questions
What is GST?
What is the full form of GST?
How do I calculate GST?
How do I remove GST from a price (reverse GST)?
What is the GST formula?
What are the GST slabs in India?
What is CGST?
What is SGST?
What is IGST?
What is the difference between CGST, SGST and IGST?
When is CGST + SGST charged vs IGST?
Who needs to register for GST?
What is the GST registration threshold?
What is Input Tax Credit (ITC)?
Can I claim Input Tax Credit?
What is a GST invoice?
What is GSTIN?
What is an HSN code?
How is GST calculated on inclusive prices?
What is the GST rate on most goods and services?
Is GST charged on the discounted price or the MRP?
What is the reverse charge mechanism (RCM)?
What is the composition scheme?
How often do I need to file GST returns?
What is GSTR-1 and GSTR-3B?
Is GST applicable on freelancers?
Do I need GST for my small business?
How does GST work for e-commerce sellers?
Is GST charged on marketplace commission?
How is GST calculated on imports?
Are exports taxed under GST?
What is a zero-rated supply?
What is the difference between exempt, nil-rated and zero-rated?
What is compensation cess?
Can GST be refunded?
What happens if I file GST late?
What is the time of supply under GST?
What is the place of supply and why does it matter?
Do I charge GST to customers outside India?
Is GST calculated before or after a discount?
How do I calculate the GST-exclusive price from an MRP?
What records must I keep for GST?
What is an e-way bill?
Can I revise a GST invoice?
How accurate is this GST calculator?
Does this calculator store my data?
Can I calculate GST for multiple products at once?
Can I generate a GST invoice with this tool?
What is the effective GST rate?
How does GST affect my profit margin?
Is GST the same as VAT?
Which countries use GST?
Written by the Omnitool Finance Team
Our editors build and maintain tax and finance calculators used for over 1.5M calculations a month, with a focus on accuracy and clarity.
Methodology reviewed
Every formula — add, remove and reverse GST, the CGST/SGST/IGST split, cess, ITC and import duty — follows the statutory GST computation rules and is independently verifiable.
Last updated June 2026
Content and default GST slabs are reviewed regularly to reflect current rates and compliance requirements.
Tax disclaimer: This GST calculator is provided for informational and educational purposes only and does not constitute tax or legal advice. GST rates, slabs, thresholds and rules change and depend on correct HSN/SAC classification and your specific circumstances. Results are estimates based on the inputs you provide. All calculations run privately in your browser — no data is uploaded or stored on our servers. Please verify the current rate on the official GST portal and consult a qualified GST practitioner or chartered accountant before filing or making business decisions.
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