Goods and Services Tax in India uses slabs. The everyday job is adding GST to a quote or backing it out of an MRP. Use the free GST calculator so the arithmetic is consistent.
Add GST
Tax = amount × rate ÷ 100. Total = amount + tax. Example: ₹1,000 at 18% → GST ₹180, total ₹1,180.
Remove GST
Exclusive = inclusive ÷ (1 + rate/100). ₹1,180 at 18% → exclusive ₹1,000.
CGST, SGST and IGST
Intra-state supplies split GST 50/50 into CGST and SGST. Inter-state supplies use IGST at the full rate. The calculator has a supply switch for this. Confirm filings with a CA. For loan maths see the EMI calculator.
