What is a GST Calculator?
The GST Calculator computes GST amounts for all five GST slabs (0%, 3%, 5%, 12%, 18%, 28%) for both intra-state (CGST + SGST) and inter-state (IGST) transactions. It works for both exclusive (add GST to price) and inclusive (extract GST from price) calculations.
Benefits of Using Rupee Logic GST Calculator
All Slabs Covered
Handles all GST rates from 0% to 28%, including the special 3% slab for gold and jewellery.
Inclusive and Exclusive
Calculate GST whether your price already includes tax or needs to have tax added on top.
CGST and SGST Split
Automatically splits intra-state GST into equal CGST and SGST halves for invoice generation.
Business Ready
Get complete invoice breakdown suitable for GST-compliant invoice preparation and filing.
Frequently Asked Questions — GST Calculator
India has five main GST slabs: 0% for essential items including fresh vegetables, milk, eggs, books, newspapers; 5% for basic necessities including edible oils, sugar, spices, tea, coal, and transport services; 12% for processed foods, computers, mobile phones, and business class travel; 18% standard rate for most goods and services including electronics, restaurants, insurance, and banking; 28% for luxury items including automobiles, tobacco, luxury hotels, and gaming.
GST registration is mandatory if: annual aggregate turnover exceeds ₹40 lakh (₹20 lakh for service providers, ₹10 lakh in special category states); you supply goods or services inter-state regardless of turnover; you are an e-commerce operator or sell through e-commerce platforms; you are liable to pay under reverse charge mechanism; or you are a casual or non-resident taxable person. Voluntary registration below these thresholds is also permitted.
CGST plus SGST are applied on intra-state transactions where buyer and seller are in the same state. Each is half the total GST rate — for 18% GST it is 9% CGST plus 9% SGST. IGST (Integrated GST) is applied on inter-state transactions between different states and on imports. IGST equals the full GST rate (18% in this case). IGST revenue is later apportioned between Central and State governments.
Small businesses with annual turnover up to ₹1.5 crore (₹75 lakh for special category states) can opt for the Composition Scheme. Flat tax rates: manufacturers 1%, restaurants 5%, other traders 1%, and service providers 6%. Benefits include simpler compliance with one quarterly return and lower tax liability. Limitations: cannot collect GST from customers, cannot claim input tax credit, and cannot supply inter-state.
Monthly filers with turnover above ₹5 crore: GSTR-1 (outward supplies) by 11th of following month; GSTR-3B (summary and payment) by 20th of following month. Quarterly filers under ₹5 crore QRMP scheme: GSTR-1 by 13th of month after quarter; GSTR-3B by 22nd or 24th of month after quarter depending on state category. Annual return GSTR-9 is due by 31st December of following financial year.