Reverse GST means finding the original pre-GST base price from an inclusive total. Formula: Base = Inclusive ÷ (1 + Rate/100). For Rs.11,800 at 18%: Base = 11800 ÷ 1.18 = Rs.10,000.
How do I find the original price before GST? +
Original Price = GST-Inclusive Amount ÷ (1 + GST Rate/100). For Rs.5,900 at 18%: Base = 5900 ÷ 1.18 = Rs.5,000. GST paid = Rs.900. This method is used in ITC claims and accounting entries.
When do I need reverse GST calculation? +
You need reverse GST when: (1) You receive an inclusive invoice and need to split base and tax for accounting. (2) You want to claim Input Tax Credit and need the exact GST component. (3) A price is quoted inclusive of GST and you want the pre-tax price. (4) Verifying whether a seller computed GST correctly.
Can CGST and SGST be different rates? +
No. CGST and SGST are always equal for any transaction — this is mandated by GST law. If total rate is 18%, CGST = 9% and SGST = 9%. IGST, used for inter-state transactions, equals the full combined rate (18%).