GST Calculator

The Goods and Services Tax (GST) is India's unified indirect consumption tax levied on the supply of goods and services. Whether you are a business owner issuing client invoices, a freelancer computing output tax, or a consumer verifying a store bill, calculating GST accurately is essential for financial clarity and statutory compliance.

The FinToolkit GST Calculator supports both GST Exclusive (adding tax to a base price) and GST Inclusive (extracting the original base price and tax component from a gross total) calculations, providing the exact CGST, SGST, and IGST breakdowns.

GST Exclusive vs GST Inclusive formulas

GST math depends on whether your starting amount includes or excludes the tax:

Intra-state vs Inter-state tax splitting

Under Indian GST law, tax revenue is divided between central and state governments based on transaction geography:

• Intra-state supply (Buyer and seller in the same state): Tax is split equally into Central GST (CGST) and State GST (SGST). For an 18% item, 9% is CGST and 9% is SGST. In Union Territories without a legislature, UTGST replaces SGST.
• Inter-state supply (Buyer and seller in different states): The entire tax is levied as Integrated GST (IGST) collected by the Central Government.

Worked GST calculation examples

Consider an invoice of ₹10,000 under the standard 18% GST rate:

Standard GST tax rate slabs in India

• 0% (Exempt): Unbranded fresh foods, milk, fresh vegetables, healthcare, and basic educational services.
• 5%: Household essentials, packaged food items, spices, footwear under ₹1,000, and economy air travel.
• 12%: Business class air travel, processed foods, computers, and medical equipment.
• 18% (Standard Rate): Most industrial goods, professional consulting, IT services, financial services, and consumer electronics.
• 28%: Luxury vehicles, aerated sodas, tobacco products, and high-end consumer appliances (often subject to an additional GST compensation cess).

Frequently asked questions

What is the threshold limit for mandatory GST registration?

For businesses dealing exclusively in goods, the mandatory GST registration threshold is ₹40 Lakh annual turnover (₹20 Lakh in special category northeastern states). For service providers, the mandatory threshold is ₹20 Lakh (₹10 Lakh in special category states).

What is Input Tax Credit (ITC)?

Input Tax Credit allows registered businesses to reduce the tax they owe on output sales by the amount of GST they have already paid on business inputs and operating purchases, preventing tax cascading.

Can a consumer claim back GST paid on shopping?

Individual end consumers cannot claim back GST paid on retail goods or restaurant dining. Only businesses registered under GST with a valid GSTIN can claim Input Tax Credit on qualifying business expenses.

Related business & tax tools

• Discount Calculator — calculate net prices after retail discounts and subsequent tax additions.
• Break-Even Calculator — determine unit volume needed to cover business overheads.
• In-Hand Salary Calculator — compute salary deductions after statutory payroll compliance.
• Income Tax Calculator (New Regime) — calculate personal income tax liability.