GST Calculator

Goods and Services Tax (GST) is India's unified indirect tax system, implemented on 1 July 2017 to replace a fragmented patchwork of central and state taxes including VAT, service tax, excise duty, and entry tax. It applies a single tax rate to most goods and services across India, with revenue split between the central government (CGST) and state governments (SGST) for intra-state transactions, or routed entirely to the central government as IGST for inter-state transactions.

GST in India operates on five primary rate slabs: 0% (essential items like fresh produce, books, healthcare), 5% (mass-consumption goods like packaged food, footwear under ₹1000, economy travel), 12% (processed food, mobile phones, business-class air travel), 18% (the standard rate for most goods and services including software, restaurants, financial services), and 28% (luxury and sin goods like cars, tobacco, premium services). A small set of items also attract additional cess.

The exclusive (or 'add GST') method calculates tax on top of a base price. If a product costs ₹1,000 before tax at 18% GST, the GST amount is ₹180 and the final invoice value is ₹1,180. The inclusive (or 'remove GST') method works backwards: if a final price already includes GST, you reverse-calculate the base price using the formula base = total × (100 ÷ (100 + rate)). For an MRP of ₹1,180 inclusive of 18% GST, the base price is ₹1,000.

Businesses with annual turnover above ₹40 lakh (₹20 lakh for service providers, with state-specific thresholds) must register for GST and file regular returns. Input Tax Credit lets registered businesses offset GST paid on purchases against GST collected on sales, which is why accurate calculation is critical — a single rate or rounding error compounds across thousands of monthly invoices.

Individuals also benefit from understanding GST when comparing pre-tax prices, validating restaurant bills, planning travel costs, or evaluating real-estate transactions. The IndCalc GST Calculator handles both directions — exclusive and inclusive — across all five primary slabs, with instant results suitable for invoicing, costing, and personal expense planning.

How do I calculate GST on a product priced at ₹2,500 with 18% GST? Multiply 2500 by 0.18 to get ₹450 in GST. Add this to the base price to get the final invoice value of ₹2,950. Use the exclusive mode in this calculator to do this in one step — enter the base amount and select 18%.

How do I extract the base price from a GST-inclusive total? Divide the total by 1 plus the GST rate as a decimal. For ₹2,950 inclusive of 18% GST: 2950 ÷ 1.18 = ₹2,500 base price, ₹450 GST. Use the inclusive mode in this calculator and enter the GST-inclusive total to extract both values automatically.

Which GST slab applies to my product or service? Most goods and services fall under the 18% standard rate. Essentials are typically 0% or 5%. Luxury items are 28%. The official GST rate finder on the cbic-gst.gov.in portal is the authoritative source — check the HSN/SAC code of your specific product or service to confirm the exact applicable rate.

What is CGST, SGST, and IGST? Intra-state transactions split GST equally between Central GST (CGST) and State GST (SGST). For 18% GST on an intra-state invoice, that's 9% CGST + 9% SGST. Inter-state transactions are charged Integrated GST (IGST) at the full 18% rate, collected by the central government and apportioned to the destination state.

Do I need to charge GST as a small business? Registration is mandatory once your annual turnover crosses ₹40 lakh for goods (₹20 lakh for services, with state-specific exceptions). Below that threshold registration is voluntary, but voluntary registration lets you claim Input Tax Credit on business purchases. Consult a CA before deciding — the right answer depends on your customer base and supply chain.