GST Calculator — Calculate GST Inclusive & Exclusive

GST Calculator India — Complete Guide to GST Rates and Calculation

Goods and Services Tax (GST) was introduced in India on July 1, 2017, replacing a complex web of central and state indirect taxes — central excise duty, service tax, VAT, CST, octroi, and entertainment tax — with a single unified tax system. India's GST is a dual structure: CGST (Central GST) collected by the central government and SGST (State GST) collected by the state government on intra-state transactions, and IGST (Integrated GST) collected by the central government on inter-state transactions. The BankZop GST Calculator handles both Add GST and Remove GST scenarios across all four standard tax slabs.

The Four GST Slabs — What Falls Where

GST Formula — Add GST vs Remove GST

Understanding the difference between GST exclusive (add GST) and GST inclusive (remove GST) is critical for invoicing, procurement, and financial planning:

• Add GST (Exclusive): Your base price does not include GST. GST Amount = Base Price × (GST Rate / 100). Total = Base Price + GST Amount. Example: ₹50,000 base + 18% GST = ₹9,000 GST = ₹59,000 total.
• Remove GST (Inclusive): Your total price already includes GST and you need the base price. Base Price = Total / (1 + GST Rate/100). GST Amount = Total − Base Price. Example: ₹59,000 inclusive of 18% GST → Base = ₹59,000 / 1.18 = ₹50,000 → GST = ₹9,000.

CGST, SGST and IGST — Which Applies to You?

For intra-state transactions (buyer and seller in the same state or union territory), GST is split equally: half goes to the central government as CGST, half to the state as SGST. For example, 18% GST on an IT service sold within Maharashtra = 9% CGST + 9% SGST. For inter-state transactions (buyer and seller in different states), the full rate is charged as IGST — collected by the centre and then apportioned to the destination state. An IT service sold from Maharashtra to Karnataka = 18% IGST. The buyer registers the IGST paid as input tax credit (ITC) in their state's books. Exports are zero-rated — 0% GST with full ITC refund.

GST on Common Business Transactions

• Professional services (CA, legal, consulting, marketing): 18% GST
• Rent on commercial property: 18% GST (if landlord is GST-registered)
• Freight and logistics: 5% GST for road transport; 18% for courier services
• Software / SaaS subscriptions: 18% GST on all digital services
• Advertising and media: 18% GST
• Construction contracts: 12% GST (with ITC); 18% on works contracts for commercial properties
• Interest income: Exempt from GST (banks and NBFCs)
• Insurance premiums: 18% GST on general insurance; 18% on term life insurance premiums

Input Tax Credit (ITC) — How Businesses Save on GST

GST-registered businesses can claim Input Tax Credit — offsetting the GST paid on purchases (inputs) against GST collected on sales (output). This prevents the cascading tax-on-tax effect of the old tax regime. Example: A manufacturer pays ₹36,000 GST on raw materials and collects ₹54,000 GST on finished goods — net GST payable to the government is only ₹18,000. ITC is available on all business purchases except personal expenses, food and beverages (unless it's your core business), motor vehicles (unless you're in the transport business), and club memberships. Consumers and composition scheme dealers cannot claim ITC.

GST Registration Threshold — When Is It Mandatory?

GST registration is mandatory if your annual aggregate turnover exceeds ₹40 lakh for goods (₹20 lakh for services, ₹10 lakh for special category states including Himachal Pradesh, Uttarakhand, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura, and Arunachal Pradesh). Voluntary registration is possible below the threshold and beneficial to claim ITC on purchases. The following must register regardless of turnover: e-commerce operators and sellers on platforms like Amazon, Flipkart, and Meesho; inter-state suppliers of goods; persons making supply through e-commerce aggregators; input service distributors; casual taxable persons; non-resident taxable persons; persons required to deduct TDS under GST (government entities); and persons required to collect TCS (e-commerce operators).

HSN Codes and SAC Codes — Classifying Goods and Services

Every product and service in the GST system is classified using a standardised code that determines the applicable tax rate. Goods use HSN (Harmonised System of Nomenclature) codes — a 4 to 8 digit international classification adopted from the World Customs Organisation (WCO). Services use SAC (Service Accounting Codes) — a 6-digit code developed by CBIC. Businesses above ₹5 crore turnover must mention 6-digit HSN codes on all B2B tax invoices. Businesses between ₹1.5–5 crore must mention 4-digit HSN. Below ₹1.5 crore, HSN is optional for B2B but mandatory for B2C invoices above ₹2.5 lakh. Common HSN codes: Chapter 84 (machinery), Chapter 85 (electronics), Chapter 61-62 (apparel), Chapter 30 (pharmaceuticals). Common SAC codes: 998311 (management consulting), 997331 (software development), 996311 (restaurant services), 997212 (renting of commercial property).

GST Returns — GSTR-1, GSTR-3B and Annual Filing

Every registered GST taxpayer must file periodic returns on the GST portal (gst.gov.in). The core return types are:

• GSTR-1: Outward supplies statement filed monthly by the 11th (or quarterly under QRMP for turnover under ₹5 crore). Contains invoice-level B2B sales, B2C large invoices above ₹2.5 lakh, exports, and credit/debit notes.
• GSTR-3B: Monthly summary return filed by the 20th. Self-declared summary of outward supplies, ITC claimed, and net tax payable. QRMP filers pay tax monthly via PMT-06 challan and file GSTR-3B quarterly.
• GSTR-9: Annual return due by December 31 of the following financial year. Mandatory above ₹2 crore turnover. GSTR-9C (self-certified reconciliation) required above ₹5 crore.
• GSTR-2B: Auto-generated monthly ITC statement — shows all available ITC based on your suppliers' GSTR-1 filings. Reconcile this with your purchase register before claiming ITC.

Late filing attracts 18% per annum interest on unpaid tax plus a late fee of ₹50/day (₹25 CGST + ₹25 SGST), capped at ₹10,000. Nil return late fee is ₹20/day.

E-Way Bill and Reverse Charge Mechanism (RCM)

Two compliance rules that go beyond just the tax rate: An E-Way Bill is a mandatory electronic document for transporting goods worth more than ₹50,000 between or within states. Generated on the e-way bill portal by the supplier, recipient, or transporter before movement begins. Valid for 1 day per 100 km distance. Missing an e-way bill can result in goods seizure and a penalty equal to 100% of the tax due. Under the Reverse Charge Mechanism (RCM), the buyer pays GST directly to the government instead of the supplier — applies to legal services from advocates, goods transport agency (GTA) services, import of services from abroad, and specific notified goods. RCM-paid GST is eligible for ITC in the same period, making it a pass-through for most registered businesses.

Zero-Rated Supplies and GST Exemptions

Not all transactions attract GST. Key distinctions: Exempt supplies (0% GST, no ITC claim allowed) include fresh produce, unprocessed grains, milk, eggs, salt, healthcare services by clinical establishments, educational services by recognised institutions, and religious services. Zero-rated supplies (0% GST, full ITC refund allowed) cover exports of goods and services and supplies to Special Economic Zones (SEZs) — exporters can claim full ITC refund on inputs. Non-GST supplies sit outside the GST framework entirely: alcohol for human consumption (state excise duty applies), petroleum products (petrol, diesel, ATF, crude oil, natural gas — still under VAT/central excise), and electricity.

Tax and Salary Tools You May Need

GST is one layer of India's tax system. BankZop's tax and salary calculators cover everything else: the TDS Calculator computes Tax Deducted at Source on salary (Sec 192), bank FD interest (Sec 194A), rent above ₹2.4 lakh/year (Sec 194I), and professional fees (Sec 194J). The In-Hand Salary Calculator breaks down your CTC to take-home salary after EPF, professional tax, and TDS. The HRA Calculator computes your House Rent Allowance exemption under Section 10(13A) to maximise ITR deductions. The Gratuity Calculator shows your payout as per the Payment of Gratuity Act, 1972, applicable after 5 years of continuous service. For business finance planning, the EMI Calculator and Loan Eligibility Calculator compare offers from banks and NBFCs. For short-term fund parking, the RD Calculator and FD Calculator help plan liquidity around GST payment dates. When paying GST challans via NEFT or RTGS, use the IFSC Code Lookup for your bank's transfer code and the BSR Code Lookup for the TDS challan BSR number.