GST Calculator - Add or Remove GST Online
Calculate Goods and Services Tax instantly. Add or remove GST with tax slabs (3%, 5%, 12%, 18%, 28%) or custom rates.
How to use GST Calculator in 3 simple steps
Enter Net or Gross Amount
Input your base or total transaction amount.
Choose Mode and Tax Rate
Select Add GST (Exclusive) or Remove GST (Inclusive), then pick a standard tax slab or enter a custom rate.
View Detailed Breakdown
See the exact base amount, CGST, SGST, IGST, and final gross total along with the calculation formula.
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Clear Goods and Services Tax Calculations
Calculating GST accurately is vital for business owners, freelancers, chartered accountants, and consumers. Knowing whether an advertised price is inclusive or exclusive of tax prevents costly billing mistakes and ensures compliance with statutory tax filings.
Toolnova GST Calculator provides bidirectional computation. You can easily add GST to a net cost to determine final invoice billing, or subtract GST from an inclusive retail price to determine the pre-tax base cost and exact tax collected.
For Indian GST compliance, the tool provides a comprehensive breakdown showing central tax (CGST) and state tax (SGST) split equally (50:50) for intra-state transactions, as well as integrated tax (IGST) for inter-state business.
Key features & capabilities
Frequently asked questions about GST Calculator
Common questions about usage, privacy, limits, and browser compatibility.
What is the formula for GST?
To add GST, multiply the base amount by the tax rate and divide by 100, then add the result to the base. To remove GST from an inclusive total, divide the total by 1 plus the rate divided by 100. The calculator displays the exact formula it used so you can check the math.
How do I remove GST from a price that already includes it?
Choose Remove GST, enter the tax-inclusive total, and select the rate. At 18%, a total of 1,180 becomes a base of 1,000 with 180 in tax, because 1,180 divided by 1.18 equals 1,000. The breakdown shows the base amount and tax separately.
What is the difference between CGST, SGST, and IGST?
For intra-state sales, the total GST rate is split evenly between CGST and SGST, so an 18% rate becomes 9% central tax and 9% state tax. Inter-state transactions are shown as IGST at the full rate. The calculator displays each of these amounts in its breakdown.
Which GST rates can I choose?
The tool includes the common 3%, 5%, 12%, 18%, and 28% slabs, plus a custom field for any other percentage. Rates vary by country and product category, so confirm the correct rate with your tax authority before billing. The calculator applies whatever rate you enter without judging whether it is right.
What do GST-exclusive and GST-inclusive prices mean?
A GST-exclusive price is the base amount before tax, so tax is added on top at checkout. A GST-inclusive price already contains the tax, which means you must divide it back out to find the taxable value. Use Add GST for the first case and Remove GST for the second.
Is my amount sent to a server?
Your amount never leaves your browser, because the GST calculation runs entirely on your device. The tool needs no account and does not store your figures on a server. That makes it convenient for checking draft invoices and client quotes on a shared or work computer.