About GST Calculator
GST (Goods and Services Tax) in India applies at 5%, 12%, 18%, or 28% depending on the category of goods or services. This calculator works in both directions: add GST to a base price, or extract the GST already included in a final price to find the original amount.
How to use
- Enter the amount you want to work with.
- Choose the applicable GST rate.
- Select whether the amount excludes or already includes GST.
- Read the tax amount and the CGST/SGST split.
The GST rate slabs
India applies GST in bands rather than at a single rate. Essential items such as fresh produce are exempt or zero-rated. A 5% band covers many everyday necessities including packaged food staples and economy transport. The 12% and 18% bands carry most standard goods and services, with 18% being the most commonly encountered rate for professional and digital services.
The top 28% band is reserved for luxury and so-called sin categories, and some of those attract an additional cess on top. Because classification follows the HSN code for goods or the SAC code for services rather than intuition, two similar-looking products can sit in different bands.
Rates are revised periodically by the GST Council, so confirm the current rate against the official CBIC schedule before relying on it for invoicing or pricing decisions.
CGST, SGST and IGST
The tax you charge is split according to where the supply moves. For a transaction within one state, the total divides evenly between Central GST and State GST — an 18% rate becomes 9% CGST plus 9% SGST, both shown separately on the invoice.
When the supply crosses a state boundary, the whole amount is charged as Integrated GST at the full rate instead. The total the customer pays is identical either way; only the split and the government receiving it change.
Getting this wrong is one of the more common invoicing errors, because it depends on the place of supply rather than simply where your business is registered.
Inclusive versus exclusive pricing
Adding GST to a base price is straightforward multiplication. Extracting it from a price that already includes tax is where mistakes happen: people often subtract 18% from the total, which is wrong.
To remove an 18% component, divide the inclusive figure by 1.18 rather than multiplying by 0.82. The difference is not trivial — on a price of 1,180, correct extraction gives a base of 1,000 and tax of 180, while subtracting 18% would wrongly suggest a base of about 967.60.
Retail prices shown to consumers in India are normally inclusive of GST, whereas quotations between businesses are frequently exclusive. Always confirm which basis a figure uses before calculating.
Frequently asked questions
How do I remove GST from an inclusive price?
Divide the inclusive price by (1 + rate/100). For an 18% rate, divide by 1.18 to get the base price; the difference is the GST component.
What is the difference between CGST and SGST?
For transactions within a single state, the total GST is split evenly between Central GST and State GST. An 18% rate becomes 9% CGST plus 9% SGST. Interstate transactions use IGST at the full rate instead.
Which GST rate applies to my product?
Rates depend on the HSN or SAC code for your specific goods or service. Essentials are often 0% or 5%, most standard goods are 12% or 18%, and luxury or sin goods fall at 28%. Check the official CBIC rate schedule to confirm.