GST Calculator

How GST Calculations Work in India

Under the Goods and Services Tax (GST) system, transactions are taxed either on an exclusive basis (adding tax to a base amount) or an inclusive basis (extracting tax from a gross price).

1. GST Exclusive Calculation (Add GST)

Used when a quote or contract price excludes taxes. The tax is added to the base assessable value:

• GST Amount = (Net Taxable Amount × GST Rate) ÷ 100
• Total Amount = Net Taxable Amount + GST Amount

Example: For an item priced at ₹10,000 with 18% GST:
GST = (10,000 × 18) ÷ 100 = ₹1,800
Total Gross Amount = 10,000 + 1,800 = ₹11,800.

2. GST Inclusive Calculation (Reverse GST Extraction)

Common in retail and consumer billing where the sticker price already includes tax. To compute the true net taxable base and extract the embedded tax:

• Net Taxable Amount = Gross Amount ÷ (1 + (GST Rate ÷ 100))
• GST Amount = Gross Amount - Net Taxable Amount

Example: For a total gross bill of ₹11,800 at 18% GST:
Net Taxable Amount = 11,800 ÷ 1.18 = ₹10,000
GST Extracted = 11,800 - 10,000 = ₹1,800.

Intra-State vs Inter-State Tax Structure

The Indian GST framework divides tax collection between the Central Government and State Governments based on the geographical location of the supplier and the Place of Supply (POS):

• Intra-State Supply (Same State): The GST rate is divided equally between CGST (Central GST) and SGST (State GST). For instance, an 18% rate is split into 9% CGST and 9% SGST.
• Inter-State Supply (Different States / UT): The full rate is levied as IGST (Integrated GST), collected centrally and redistributed to the destination state.

Indian GST Rate Slabs

• 0% (Exempt / Nil Rated): Essential food grains, fresh produce, unbranded dairy, books, healthcare, and educational services.
• 5%: Packaged food items, apparel below ₹1,000, transport services, domestic LPG, and basic medicines.
• 12%: Processed foods, business class air tickets, select business IT hardware, and work contracts.
• 18% (Standard Rate): Most industrial goods, professional software services, IT consulting, capital machinery, telecommunications, and financial services.
• 28%: Luxury automobiles, tobacco products, pan masala, and aerated beverages (often accompanied by GST Compensation Cess).

Frequently Asked Questions