GST Calculator (India)
Calculate GST at 5%, 12%, 18% or 28%, adding or removing it from an amount.
Your figures
Result
How to use this tool
- Enter your own figures over the defaults — Amount, GST rate, Amount is.
- The answer updates as you type. There is no button, and nothing is sent anywhere.
- Change Amount on its own to see how much it moves the result — the worked example below shows exactly that.
For supplies within a state, GST splits equally into CGST and SGST. For interstate supplies it is charged as a single IGST at the same total rate.
How it works
This takes 3 inputs — amount, gst rate, amount is — and returns total including gst, gst at 18% and cgst / sgst (half each). The whole calculation happens in this page as you type: there is no submit button, no request, and nothing stored.
Because it recalculates on every keystroke you can use it as a sensitivity test rather than a one-shot answer. Moving amount alone from 1,000 to 1,100 changes total including gst from 1,180.00 to 1,298.00 — the worked example below sets that out in full.
A worked example
Worked through with the figures the page already has in it: amount of 1,000 and gst rate of 18, and the rest as shown, giving total including gst of 1,180.00. These numbers come from running the calculator’s own code, not from being typed in here, so they cannot drift away from what you see on screen.
Starting from:
- Amount: 1,000
- GST rate: 18
- Amount is: Excluding GST
| Result | Value |
|---|---|
| Total including GST | 1,180.00 |
| GST at 18% | 180.00 |
| CGST / SGST (half each) | 90.00 |
What happens when one input moves
Holding everything else steady and changing Amount from 1,000 to 1,100 — 10% — moves the answer like this:
| Figure | 1,000 | 1,100 |
|---|---|---|
| Total including GST | 1,180.00 | 1,298.00 |
| GST at 18% | 180.00 | 198.00 |
| CGST / SGST (half each) | 90.00 | 99.00 |
That is usually the number worth arguing over: it is easier to move than the headline amount, and the difference compounds across the whole term.
GST Calculator (India) — frequently asked questions
What are CGST, SGST and IGST?
For a sale within one state, the total GST splits equally between Central GST and State GST. For a sale across state lines, the same total is charged as a single Integrated GST.
How do I remove GST from an inclusive price?
Divide by (1 + rate/100). At 18%, divide the gross by 1.18.
Which rate applies to my goods?
Rates are set by HSN code and change periodically. Check the current rate schedule for your specific classification.
Is this calculator free?
Yes, with no account, no limits and no data collection. It runs entirely in your browser.
Should I rely on this for a financial or medical decision?
No. It is a planning estimate built on standard formulas and stated assumptions. For decisions that matter, speak to a qualified professional who can account for your full circumstances.
How accurate is the GST Calculator (India) figure?
The arithmetic is exact. With the defaults on this page — amount 1000, gst rate 18, amount is Excluding GST — it returns total including gst of 1,180.00. What limits accuracy is the assumptions, not the maths: change amount to 1100 and the same formula gives 1,298.00. Treat it as a well-founded estimate, not a quotation.
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Nothing is sent anywhere. The figures you type stay in this page and are never transmitted or stored — how that works.
Disclaimer. The formula is exact; the answer is only as good as the figures and assumptions above. Not financial, tax, medical or legal advice. Full disclaimer.