How to Calculate Your GST Using a GST Calculation Formula?

Taxpayers are now aware of the amount of tax charged at each point of supply for products and services thanks to the implementation of GST. When calculating GST, taxpayers must be aware of the GST rates applicable to different categories.

Updated On - 06 Sep 2025

 Under the new tax structure, the rates applicable are 5%, 12%, 18% and 28%.

GST Calculation Formula

The below mentioned formula is for calculating GST by taxpayer:

  1. Add GST
    1. GST Amount = (Original Cost x GST%)/100Net Price = Original Cost + GST Amount
  1. Remove GST
    1. GST Amount = Original Cost - [Original Cost x {100/(100+GST%)}]Net Price = Original Cost - GST Amount

To calculate GST (Goods and Services Tax), you need to follow these steps:

Step 1: Check the GST rate applicable for the goods or services you are selling or purchasing.

Step 2: Determine the transaction value of the goods or services on which GST is to be calculated.

Step 3: Calculate the GST amount by multiplying the transaction value with the applicable GST rate.

Step 4: Determine the gross amount payable by adding the GST amount to the transaction value.

Example of GST Calculation

In case a product is sold for Rs.5,000 and the GST rate applicable to it is 12%

Then, the net price of the product will be Rs.5,000 + 12% of Rs.5,000 = Rs.5,000 + Rs.600 = Rs.5,600.

Tax Calculation under GST System

Under the GST regime, manufacturers and dealers can benefit from input tax credit.

Below is an example to show the difference in the amount of tax payable under the old tax system and the GST system:

Value to Manufacturer

Old Tax system

GST System

Cost of production

Rs. 3,00,000

Rs.3,00,000

Profit Margin of 10%

Rs.30,000

Rs.30,000

Excise duty of 12%

Rs.36,000

-

Total production cost

Rs.3,66,000

Rs.3,30,000

VAT of 12.5%

Rs.45,750

-

SGST of 6%

-

Rs.19,800

CGST of 6%

-

Rs.19,800

Invoice value for manufacturer

Rs. 4,11,750

Rs. 3,69,600

Value to Wholesaler

-

-

Cost of goods

Rs. 4,11,750

Rs. 3,69,600

Profit margin of 10%

Rs. 41,175

Rs. 36,960

Total Value

Rs. 4,52,925

Rs. 4,06,560

VAT of 12.5%

Rs. 56,615

-

SGST of 6%

-

Rs. 24,393

CGST of 6%

-

Rs.24,393

Invoice value to wholesaler

Rs. 5,09,540

Rs. 4,55,346

Value to Retailer

-

-

Cost of goods

Rs. 5,09,540

Rs. 4,55,346

Profit margin of 10%

Rs. 50,954

Rs. 45,534

Total Value

Rs.5,60,494

Rs. 5,00,880

VAT of 12.5%

Rs. 70,061

-

SGST of 6%

-

Rs. 30,052

CGST of 6%

-

Rs. 30,052

Invoice value to retailer

Rs.6,30,555

Rs. 5,60,984

Impact of GST on Product Pricing

Indirect tax will be levied by Central and State Government called Central GST (CGST) and State GST (SGST), respectively. In the case of intra-state transactions, the seller will collect CGST and SGST from the buyer which will be paid to the Central and State Government, respectively. Listed below is an example of the impact of GST on product pricing:

Old Tax System

GST System

Price of a product sold from Pune to Jaipur = Rs.1,000

Price of a product sold from Pune to Jaipur = Rs.1,000

VAT @ 10% = Rs.100

CGST @ 5% = Rs.50 + SGST @ 5% = Rs.50

Cost of a product sold from Pune to Jaipur = Rs.1,100

Cost of a product sold from Pune to Jaipur = Rs.1,100

Profit = Rs.1,000

Profit = Rs.1,000

Selling Price = Rs.2,100

Selling Price = Rs.2,100

CST @ 10% = Rs.210

IGST @ 10% = Rs.110

Total cost of the product = Rs.2,310

Total cost of the product = Rs.2,210

Benefits of GST Calculator

Here are some of the key benefits of using a GST calculator:

  1. It enables users to determine the net or gross product price on GST rates.
  2. It enables users to differentiate between SGST, CGST and IGST and calculate each tax accurately.
  3. It saves time by providing instant results.
  4. It lowers the risk of human error when calculating the cost of products and services.
  5. It is simple to use and helps you calculate GST in a hassle-free manner.

GST Bill Rates and Their Calculation

The GST Bill is touted to be a landmark bill with respect to taxation in India. This Bill is being implemented with the intention of curbing 'double-taxation' and irregularities regarding the same. On 29 March, 2017 four bills were approved.

The government has set a deadline of 1, July 2017 for the complete implementation of this Bill. A number of products and services would become cheaper and others would become heavier on the wallet.

However, instead of the expected single tax slab, a multi-tier tax slab has been put forth with four different tax rates of 5%, 12%, 18% and 28%. The justification behind this multi-tier system is that essential goods and services cannot be taxed at the same rate as luxury products and services.

It is essential to note that the GST Bill has two components to it - one that is levied by the Centre which is known as CGST or Central GST and the other which is levied by all States known as SGST or State GST.

Rates for each would be approved based on revenue and acceptability, among other factors. Except for those goods and services that have been exempted, SGST and CGST will be applicable on all goods and services. Both Centre and States would have jurisdiction for the determination of tax rates and for all taxpayers based on the threshold for products and services that have been prescribed.

From the example, it's clear that subsuming excise duty is favourable to the end consumer. There is a reduction in cost for manufacturers, wholesalers, and retailers due to the subsuming of VAT, Service Tax, and Excise duty. Due to the reduction in cost, there will be a reduction in input tax credit.

Tax Calculation for Inter-State Sales

Integrated GST (IGST) will be levied by the Central Government on inter-state supply of goods and services. In the case of inter-state transactions, IGST will be transferred to importing state.

In the old tax system, CST was charged over and above VAT and the excise duty for movement of goods between 2 states. In the GST system, IGST is the only tax levied on goods moving across state borders. Below is an example to understand the IGST system:

Value to Manufacturer

Old Tax System

GST System

Cost of goods

Rs.1,00,000

Rs.1,00,000

VAT of 12.5%

Rs.12,500

-

IGST of 12%

-

Rs.12,000

CST of 2%

Rs.2,250

-

Total value to retailer

Rs.1,14,500

Rs.1,12,000

As per the above example, it is clear that under the GST system, manufacturers, wholesalers, and retailers will see reduction in cost whether it is inter-state or intra-state sales.

Benefits of GST Implementation in India

Implementing a single indirect tax is beneficial in many ways such as:

  1. It not only helps in setting an international standard but also ensures transparency throughout the tax structure right from the manufacturer to the consumer.
  2. The primary objective of implementing GST is to prevent double taxation of commercial goods. GST is expected to ultimately increase competition among the manufacturers and sellers to provide high-quality goods which in turn will boost the GDP of the country.
  3. The reduce in tax will bring down the production cost for companies. Thus, increase the competition among exporters.
  4. Inflation is expected to decrease after the implementation of GST.
  5. It is also said that there will be a decrease in tax liability. Reduction in price is expected as input tax credit is available against output tax. Following taxes will be set-off with the same or with the different tax input credits

CGST

CGST and IGST

SGST

SGST and IGST

IGST

IGST , CGST and SGST

Recent Changes in GST Calculation Rules

  1. As observed in the previous examples, there have been changes noted in the type of tax and amount imposed.
  2. Excise is generally applicable on capital goods during production used by manufacturer. Under the new Bill, excise on capital goods will be subsumed as there will only be a single rate of tax for each type of product.
  3. Due to the subsuming of Service Tax, VAT, Excise, there will be a fall in the cost of wholesalers, manufacturers and retailers. This will in turn reduce the total cost to the manufacturer due to a reduction in procurement cost.
  4. There will also be a fall in input tax credit for the retailer/wholesaler under GST.

Therefore, as observed there will be a fall in prices for the manufacturer. However, changes in GST rates will depend on the products and services.

FAQs on GST Calculator

  • What is a GST calculator?

    A GST calculator is a tool that helps to calculate the GST amount payable or inclusive in a transaction based on the applicable GST rate.

  • How does a GST calculator work?

    A GST calculator works by taking inputs such as the transaction value, applicable GST rate, and type of transaction (i.e., whether it is taxable or exempt) and calculating the GST amount payable or inclusive in the transaction.

  • What are the benefits of using a GST calculator?

    The benefits of using a GST calculator include accurate and quick calculation of GST, avoidance of errors in GST calculation, and compliance with GST regulations.

  • Are there any online GST calculators available?

    Yes, there are many online GST calculators available that can be used for free.

  • Is it mandatory to use a GST calculator for GST calculation?

    No, it is not mandatory to use a GST calculator for GST calculation, but it is recommended for accurate calculation of GST.

  • Can a GST calculator be used for reverse charge mechanism (RCM) transactions?

    Yes, a GST calculator can be used for RCM transactions by selecting the appropriate option in the calculator.

  • Can a GST calculator be used for multiple GST rates?

    Yes, a GST calculator can be used for multiple GST rates by entering the applicable rate for each item or service in the transaction. 

  • Is GST applicable on all goods and services?

     No, GST is not applicable on all goods and services. Some goods and services are exempt from GST, while others are taxed at different rates.

  • What is the current GST rate in India?

    The current GST rate in India varies from 0% to 28% depending on the goods or services being taxed.

  • Is GST Applicable on International Transactions?

    No, a GST calculator cannot be used for international transactions as GST is a tax levied by the Indian government on domestic transactions only.

  • How is GST calculated on advance payments?

    GST on advance payments is calculated based on the rate applicable on the goods or services that will be supplied in the future. The supplier needs to issue a tax invoice or a receipt voucher showing the GST charged on the advance payment.

  • How do I calculate GST on discounted prices?

    GST is calculated on the final selling price of the goods or services, including any discounts or offers. So, to calculate GST on discounted prices, the reduced selling price should be used to apply the applicable GST rate.

  • How do I calculate GST on composite supply?

    For composite supply, GST is calculated on the principal supply that gives the composite supply its essential character. The GST rate applicable on the principal supply is used to calculate the GST amount for the composite supply.

Disclaimer
Display of any trademarks, tradenames, logos and other subject matters of intellectual property belong to their respective intellectual property owners. Display of such IP along with the related product information does not imply BankBazaar's partnership with the owner of the Intellectual Property or issuer/manufacturer of such products.