taxInvoice.appGST calculator (India)
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GST formula
| Task | Formula | Example at 18% |
|---|---|---|
| Add GST | GST = amount x rate / 100 | 1,000 x 18% = 180; total 1,180 |
| Remove GST | Net = total x 100 / (100 + rate) | 1,180 x 100 / 118 = 1,000; GST 180 |
| CGST / SGST | Each = GST / 2 | 90 + 90 |
Related guides
Frequently asked questions
How do I add GST to a price?
Multiply the price by the GST rate. For 18%: GST = price x 0.18, total = price x 1.18. Rs. 1,000 + 18% GST = Rs. 1,180.
How do I remove GST from a total (reverse GST)?
Divide the total by (1 + rate). For 18%: net = total / 1.18, GST = total - net. Rs. 1,180 includes Rs. 180 GST.
When is GST split into CGST and SGST?
When the supplier and the place of supply are in the same state, the GST is split equally into CGST and SGST. For supplies to another state, the whole amount is IGST.
Which GST rate applies to my product?
It depends on the HSN or SAC code. Check the current GST rate schedule; rates were rationalised in 2025 and can change.