GST Calculator 2026
Add or remove GST at 5%, 18%, or 40%. Get the CGST/SGST split for intrastate or IGST for interstate transactions.
You enter the base amount; we add GST on top.
Final amount
₹11,800
GST @ 18% — ₹1,800
Breakdown
The Indian GST Framework: Demystifying Slabs, Reverse Charge, and Inter-State Rules
The Goods and Services Tax (GST) operates on a dual architecture: Intra-State transactions split tax equally between Central GST (CGST) and State GST (SGST), while Inter-State commerce levies Integrated GST (IGST) directly to the central exchequer.
GST Rates & Invoicing FAQs
Helpful indirect tax answers for Indian businesses and consumers.
What is the mathematical formula to extract GST from an inclusive price?
GST Amount = Inclusive Price − [Inclusive Price ÷ (1 + GST Rate ÷ 100)]. For instance, if an item costs ₹118 inclusive of 18% GST: Base Cost = 118 ÷ 1.18 = ₹100, and GST Amount = ₹18.
What is the mandatory threshold for GST registration in India?
For businesses supplying goods, the threshold is ₹40 Lakhs aggregate annual turnover (₹20 Lakhs in special category states). For service providers, the mandatory threshold is ₹20 Lakhs (₹10 Lakhs in special category states).
When does e-Invoicing become legally mandatory for businesses?
Under current CBIC notifications, e-Invoicing is mandatory for all registered businesses whose aggregate turnover in any preceding financial year from 2017-18 onwards exceeds ₹5 Crores.
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