GST Reverse Calculator

What is GST Reverse Calculation?

GST Reverse Calculation is the process of finding the original base price (price before GST) from a GST-inclusive amount. When you purchase a product or service in India, the price you pay usually includes GST. This calculator helps you reverse-engineer the base price and determine exactly how much GST was included in the total amount. This is useful for accounting, filing GST returns, claiming input tax credits and verifying invoices.

How to Use This Calculator

Enter the total GST-inclusive amount and select the applicable GST rate (5%, 12%, 18%, 28%, or enter a custom rate). The calculator will show:

• Base Price: The original price before GST.
• CGST: Central GST (half of total GST for intra-state transactions).
• SGST: State GST (half of total GST for intra-state transactions).
• Total GST: The complete GST amount included in the price.
• Total Amount: Verification of the original inclusive amount.

Formula

The reverse GST formula is:

Base Price = GST-Inclusive Amount x (100 / (100 + GST Rate))

GST Amount = GST-Inclusive Amount - Base Price

CGST = GST Amount / 2

SGST = GST Amount / 2

For example, if the GST-inclusive amount is ₹11,800 at 18% GST: Base Price = 11,800 x (100/118) = ₹10,000. Total GST = ₹1,800. CGST = ₹900. SGST = ₹900.

Frequently Asked Questions

What GST rates apply in India?

India has four main GST slabs: 5%, 12%, 18% and 28%. Essential items like food grains attract 0% or 5%, while luxury goods and certain services attract 28%. Most commonly used goods and services fall under the 12% or 18% slab.

What is the difference between CGST and SGST?

CGST (Central Goods and Services Tax) goes to the Central Government, while SGST (State Goods and Services Tax) goes to the State Government. For intra-state transactions, the total GST is split equally between CGST and SGST. For inter-state transactions, IGST (Integrated GST) is charged instead.

When would I need a GST reverse calculator?

You need a reverse GST calculator when you have an invoice that shows only the total amount including GST, and you want to find the base price for accounting, input tax credit claims, or expense reporting purposes.