What is GST in India?
Goods and Services Tax (GST) is India's unified indirect tax system, introduced on 1 July 2017, replacing multiple cascading taxes including VAT, Service Tax, Excise Duty, and Octroi. GST is a destination-based, multi-stage tax levied on every value addition in the supply chain.
GST has dramatically simplified taxation, increased compliance, and unified India's economy under "One Nation, One Tax." Over 1.4 crore businesses are registered under GST as of 2025.
GST Calculation Formulas
Adding GST to Base Amount (Exclusive)
Total = Base + GST Amount
Example: Base ₹10,000 + 18% GST = ₹10,000 + ₹1,800 = ₹11,800
Removing GST from Total Amount (Inclusive)
GST Amount = Total – Base
Example: Total ₹11,800 inclusive of 18% GST → Base = ₹11,800/1.18 = ₹10,000, GST = ₹1,800
Types of GST in India
CGST (Central GST)
Collected by Central Government on intrastate supplies. Applies equally with SGST on transactions within the same state.
SGST (State GST)
Collected by State Government on intrastate supplies. Applies equally with CGST.
IGST (Integrated GST)
Collected by Central Government on interstate transactions. Equal to combined CGST + SGST rate.
UTGST (Union Territory GST)
Collected on supplies within Union Territories without legislature (Chandigarh, Lakshadweep, etc.).
GST Rate Slabs in India 2025
- 0% (Exempt): Fresh vegetables, milk, eggs, unbranded flour, postal services
- 5%: Essential medicines, packaged food, economy transport, footwear under ₹1000
- 12%: Processed food, business class flights, computers, mobile phones
- 18%: IT services, telecom, restaurants, hotel rooms ₹1000-7500
- 28%: Luxury cars, tobacco, aerated drinks, hotel rooms above ₹7500
- 28% + Cess: Pan masala, gutkha, luxury goods
Who Should Register for GST?
- Businesses with turnover above ₹40 lakh (₹20L for services, ₹10L for special states)
- Interstate suppliers (regardless of turnover)
- E-commerce sellers
- Casual taxable persons
- Non-resident taxable persons
- Input Service Distributors
Benefits of Using a GST Calculator
- Time-Saving: Instant computation vs manual calculation
- Error-Free: No arithmetic mistakes on invoices
- Both Modes: Add GST or extract GST from total
- Detailed Breakdown: See CGST, SGST, IGST split clearly
- Free & Unlimited: Use as many times as needed
- Mobile Friendly: Calculate on-the-go from anywhere
Input Tax Credit (ITC) — Save More with GST
Input Tax Credit allows businesses to deduct the GST paid on purchases (inputs) from the GST collected on sales (output). This avoids tax cascading and is one of GST's biggest advantages over the old tax system.
For example, if you collect ₹10,000 GST on sales and paid ₹6,000 GST on purchases, you only need to pay ₹4,000 (net) to the government.
GST Return Filing Schedule
- GSTR-1: Monthly/Quarterly sales return (11th of next month)
- GSTR-3B: Monthly summary return (20th of next month)
- GSTR-9: Annual return (31st December)
- GSTR-4: Composition scheme annual return (30th April)