GST Calculator
Calculate GST amount and total price, inclusive or exclusive of tax.
How it works
Goods and Services Tax (GST) calculations trip people up in one specific way: whether the amount you have already includes tax or not. Get that wrong and every downstream number -- invoice totals, margins, tax filings -- is off. This calculator handles both directions correctly.
If you have a base price and need to add GST on top (exclusive), it calculates the tax amount and adds it to give you the final price. If you already have a GST-inclusive amount -- say, an MRP or a total invoice figure -- and need to know how much of that is the base price versus the tax component, the calculator extracts that split for you using the correct inclusive formula (dividing by 1 + rate/100, not simply subtracting the percentage).
Works for any GST rate -- 5%, 12%, 18%, 28%, or any custom rate -- making it useful beyond India's standard slabs for any percentage-based tax calculation.
Formula
GST = Amount × Rate / 100
Added on top of the base amount.
Base = Amount / (1 + Rate/100)
Extracted from a tax-inclusive total.
Frequently asked questions
What's the difference between inclusive and exclusive GST?
Exclusive means GST is added on top of your entered amount. Inclusive means your entered amount already contains GST, and the calculator extracts the base price.
Why can't I just subtract the percentage for inclusive GST?
Because the percentage was applied to the base price, not the total. Subtracting 18% directly from a GST-inclusive total overstates the tax removed -- you need to divide by (1 + rate/100) to correctly reverse the calculation.
What are the standard GST rates in India?
The common slabs are 5%, 12%, 18% and 28%, depending on the category of goods or services. This calculator works with any rate you enter, not just these four.
Can I use this for VAT or other percentage-based taxes?
Yes -- the underlying math (adding or extracting a percentage-based tax) is the same regardless of what the tax is called in your country.