GST Calculator
Add GST to a base price, or work backwards from a GST-inclusive total to find the tax and net amount, at any rate you enter.
How to use the GST Calculator
- Enter the amount.
- Choose whether that amount already includes GST or not.
- Pick or type the rate and read the base amount, tax amount and total.
About the GST Calculator
The reverse calculation is where most errors happen: taking 18% off an inclusive price is not the same as dividing by 1.18, and using the wrong one leaves your invoice out by a few percent. This tool handles both directions explicitly and shows the base amount and tax component on separate lines so you can copy them straight into an invoice or a return.
Frequently asked questions
How do I remove GST from an inclusive price?
Divide the total by (1 + rate/100). At 18%, divide by 1.18 — subtracting 18% gives the wrong answer.
Which GST rates can I use?
Any. The common slabs are preset, and you can type a custom rate for VAT or sales tax in other countries.
Does it split CGST and SGST?
It gives the total tax; for an intra-state Indian invoice, halve that figure between CGST and SGST.
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