GST Calculator: Calculate Your GST Amount Online

want to know how much GST are you paying on a product that you purchase? Just put the amount you paid and GST percentage.

Amount *

About Finology GST Calculator


GST which refers to Goods & Service Tax, is an indirect tax reform which ultimately aims at removing the tax barriers between states and create a single market which is open to all to buy, sell, import, export within the country. It’s exclusively designed & has a class within it which provides economic freedom to traders. Before GST, there were more than 17 Indirect Taxes but GST subsumed all and became a single indirect tax for the whole nation, which led to the “ONE NATION ONE TAX” structure.

GST is divided into five different tax slabs for collection of tax - 0%, 5%, 12%, 18% AND 28%. Before GST there was a huge ambiguity on the applicable tax rates on different products, however GST has introduced HSN code (a 4-8 digit code) which helps in identifying the applicable rate of GST on different products. The country is divided into two halves, one is the state where your business is located and the other half consists of other states of India.


We already know about the 5 different slab rates that are applicable on different products. Now, let’s see “How to apply these tax rates on the value of product to calculate GST Payable?”

For this purpose, let us take an Example:

Before I tell you, please understand 2 terms:-

  • i) Taxable Value (exclusive of GST)- The value on which GST is applicable i.e., the value on which GST is not charged and added till yet & we are required to charge GST on this value.
  • ii) Invoice Value (inclusive of GST)-It is the sum total of Taxable value + GST amount.

Mr. A, who lives in Raipur (C.G.), purchased a Good from a local dealer worth Rs. 100. Now Rs. 100 is the taxable value and we have to charge GST on this value. Suppose this product attracts 18% GST. Hence GST amount = 100*18% = 18. Since it is within state purchase, hence

CGST=9% i.e., Rs. 9

SGST=9% i.e., Rs. 9 would be applicable.

Now, if Mr. A would have purchased it outside C.G., then it would have attracted IGST i.e. a single tax amounting to Rs.18. Hence the total price that Mr. A would be required to pay to the shopkeeper is Rs.100 + Rs.18 = Rs.118.

Outward Supply: Mr. B is a dealer of grocery items in C.G., he sells 100 bottles of oil worth Rs. 10 each to Mr. A who is a seller in Odisha. Amount & category of GST to be charged would be –

Since Mr. A lives in Odisha and purchases oil from dealer in C.G., he is required to pay IGST.

Taxable Value of oil= 100 bottles x Rs. 10= Rs. 1000.

IGST= 1000 X 18%= Rs. 180.

Invoice Value i.e., the amount payable by Mr. A will be Rs. 1000 + Rs. 180= Rs. 1180

3. Reverse Calculation of GST from Invoice Value

Suppose you purchased a plastic bottle from a shop for Rs.100 and it was inclusive of GST rated 18%. Now if you want to calculate the amount of GST you paid on it, use this formula –

[100 X (Tax Rate/ 100+Tax Rate)]

i.e., GST= [100 x (18/118)] = Rs. 15.254

Taxable Value i.e., value exclusive of GST = Rs.100 - Rs.15.254 =Rs.84.745

4. How to use this GST calculator

Since the above mentioned process of calculation is little bit complex and confusing, we made it easy for you.

Steps for using this calculator –

  • First of all, select GST exclusive/inclusive as per your need.
  • Enter the original amount.
  • Select your required GST rate from the drop down given.
  • Select CALCULATE GST to get the results.

5. Evaluate Results.

GST Exclusive: Since the amount is exclusive of GST, Enter Taxable value here i.e., the actual price of the product without GST. It will give you the GST amount & POST-GST amount i.e., after adding the GST.

GST Inclusive: Since this amount is inclusive of GST, enter the Invoice value here i.e., the price of the product after adding GST. It will give you the GST amount & PRE-GST amount i.e., after deducting the GST.