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GST Calculator – Add or Remove GST

Calculate GST amounts, add GST to a price, or remove GST from an inclusive price with our easy-to-use calculator.

Last updated: April 2026

Original Amount
1000.00
GST Amount (18%)
180.00
Total Amount
1180.00
GST Breakdown

CGST (9%)

90.00

SGST (9%)

90.00

ComponentRateAmount (₹)
Original Amount-1000.00
CGST9%90.00
SGST9%90.00
Total GST18%180.00
Final Amount-1180.00

What is a GST Calculator?

A GST (Goods and Services Tax) calculator is a financial tool designed to help individuals and businesses calculate the GST component of a transaction. It can be used in two primary ways: to add GST to a price (GST-exclusive to GST-inclusive calculation) or to extract the GST amount from a price that already includes GST (GST-inclusive to GST-exclusive calculation).

In India, GST is a comprehensive indirect tax that has replaced multiple taxes like VAT, service tax, and excise duty. It follows a multi-tier structure with different rates (5%, 12%, 18%, and 28%) applicable to different categories of goods and services. For intra-state transactions, GST is divided equally between Central GST (CGST) and State GST (SGST).

This calculator simplifies GST calculations for various purposes such as invoice preparation, expense management, input tax credit calculations, and understanding the tax component of purchases. It's particularly useful for businesses, freelancers, and consumers who need to quickly determine the GST amount or the pre-GST value of goods and services.

How to use this calculator

  1. 1
    Select the calculation typeChoose whether you want to add GST to an amount or remove GST from an amount that already includes it.
  2. 2
    Enter the amountInput the original amount (if adding GST) or the GST-inclusive amount (if removing GST).
  3. 3
    Select the GST rateChoose the applicable GST rate from the common options (5%, 12%, 18%, 28%) or enter a custom rate.
  4. 4
    View the resultsThe calculator will instantly show the GST amount, the total amount, and the breakdown of CGST and SGST components.
  5. 5
    Check the detailed breakdownReview the detailed breakdown of all components and the formulas used for the calculation.

Formula & example

GST Amount = Original Amount × (GST Rate ÷ 100)

GST Amount= The tax amount to be added
Original Amount= The pre-tax value of goods or services
GST Rate= The applicable GST percentage (5%, 12%, 18%, or 28%)

Let's calculate GST for a product with the following parameters:

  • Original Amount (pre-GST): ₹1,000
  • GST Rate: 18%

Adding GST:

GST Amount = Original Amount × (GST Rate ÷ 100)

GST Amount = ₹1,000 × (18 ÷ 100)

GST Amount = ₹1,000 × 0.18

GST Amount = ₹180

Total Amount = Original Amount + GST Amount

Total Amount = ₹1,000 + ₹180 = ₹1,180

Removing GST:

If we have a GST-inclusive amount of ₹1,180 and need to find the original amount:

Original Amount = GST-inclusive Amount ÷ (1 + GST Rate ÷ 100)

Original Amount = ₹1,180 ÷ (1 + 18 ÷ 100)

Original Amount = ₹1,180 ÷ 1.18

Original Amount = ₹1,000

GST Amount = GST-inclusive Amount - Original Amount

GST Amount = ₹1,180 - ₹1,000 = ₹180

CGST and SGST Breakdown:

For intra-state transactions, GST is divided equally between CGST and SGST:

CGST = GST Amount ÷ 2 = ₹180 ÷ 2 = ₹90

SGST = GST Amount ÷ 2 = ₹180 ÷ 2 = ₹90

Benefits

Invoice Preparation

Quickly calculate the GST amount to add to your invoices or bills, ensuring accurate tax collection.

Budget Planning

Understand the total cost including taxes when planning purchases or estimating project costs.

Input Tax Credit Calculation

For businesses, easily determine the input tax credit that can be claimed on purchases.

Price Comparison

Compare prices on a pre-tax basis when different vendors quote prices with and without GST included.

Tax Component Analysis

Analyze how much of your payment goes towards taxes versus the actual value of goods or services.

Compliance Verification

Verify that the correct GST amount has been charged on invoices received from suppliers.

Use cases

Business Invoicing

Small businesses and freelancers can use the calculator to add the correct GST amount to their invoices, ensuring compliance with tax regulations while providing transparent billing to their clients.

Expense Management

Finance teams can extract the pre-GST value from expense reports to properly categorize and account for expenses, separating the actual cost from the tax component for accurate financial reporting.

Retail Pricing Strategy

Retailers can calculate both GST-exclusive and GST-inclusive prices to determine optimal pricing strategies, ensuring their margins are maintained after accounting for tax obligations.

Consumer Purchase Decisions

Consumers can understand the actual value of products by removing GST from displayed prices, helping them make more informed purchase decisions based on the true value of goods rather than the tax-inflated price.

Frequently asked questions

What is GST?+

Goods and Services Tax (GST) is a comprehensive indirect tax levied on the supply of goods and services in India. It replaced multiple taxes like VAT, service tax, and excise duty. GST is a destination-based tax collected at every stage of the value addition chain, with a provision for input tax credit.

How is GST calculated?+

To add GST to a price, multiply the original amount by the GST rate percentage and divide by 100. For example, to add 18% GST to ₹1,000: GST amount = ₹1,000 × 18 ÷ 100 = ₹180. The total amount would be ₹1,180. To remove GST from an inclusive price, divide the amount by (1 + GST rate/100). For example, to find the original price from ₹1,180 with 18% GST: Original price = ₹1,180 ÷ 1.18 = ₹1,000.

What are the different GST rates in India?+

India follows a multi-tier GST structure with four main rates: 5% (essential items), 12% (standard rate for many goods), 18% (standard rate for services and many goods), and 28% (luxury and sin goods). Some items are exempt from GST (0%), and some luxury and sin goods attract additional cess on top of the 28% GST.

What is the difference between CGST, SGST, and IGST?+

CGST (Central GST) and SGST (State GST) are collected on intra-state transactions (within the same state). Each is half of the total GST rate. For example, for an 18% GST rate, 9% is CGST and 9% is SGST. IGST (Integrated GST) is collected on inter-state transactions (between different states) and is the full GST rate. For imports, IGST is applicable.

How do I know if a price includes GST or not?+

By law, businesses must clearly mention whether their quoted prices are inclusive or exclusive of GST. If a price is mentioned as 'inclusive of GST' or 'GST included', it means the stated price already includes the GST component. If not specified or mentioned as 'plus GST' or 'GST extra', it means GST will be added to the stated price.

Can I claim input tax credit on GST paid?+

Yes, if you are a GST-registered business, you can claim input tax credit (ITC) for the GST paid on purchases used for business purposes. This helps avoid tax cascading (tax on tax). However, there are certain restrictions on claiming ITC for specific items and services as per GST regulations.

How do I calculate GST for different tax rates in a single invoice?+

For invoices with items having different GST rates, calculate the GST for each item separately based on its applicable rate, and then add them up for the total GST amount. For example, if an invoice has items worth ₹1,000 at 5% GST and ₹2,000 at 18% GST, the total GST would be (₹1,000 × 5% = ₹50) + (₹2,000 × 18% = ₹360) = ₹410.