How GST is calculated
To add GST: GST = Amount × Rate ÷ 100. To remove GST from an inclusive price: Net = Amount × 100 ÷ (100 + Rate).
CGST, SGST and IGST
For a sale within the same state, the GST is split equally into CGST and SGST. For a sale to another state, the full amount is charged as IGST. The main slabs are 5%, 18% and 40% after the September 2025 GST revision.