Add GST: Total = Base × (1 + Rate/100) Remove GST (Reverse): Base = Inclusive ÷ (1 + Rate/100) CGST = SGST = GST Amount ÷ 2 (intra-state) IGST = Full GST amount (inter-state)
Source: GST Council — slabs unchanged for FY 2026-27
Frequently Asked Questions
Multiply base price by 1.18. Example: ₹1,000 + 18% GST = ₹1,180. GST amount = ₹180 (CGST ₹90 + SGST ₹90 for intra-state). For inter-state supply, IGST of ₹180 applies.
Use the 'Remove GST' mode. Formula: Base = Inclusive ÷ (1 + Rate/100). Example: ₹1,180 including 18% GST → Base = ₹1,180 ÷ 1.18 = ₹1,000. Many calculators incorrectly subtract 18% directly giving ₹967.60 — that is wrong.
Four main slabs: 5% (essentials), 12% (processed food, business travel), 18% (most services and manufactured goods — the most common rate), 28% (luxury). Many items are 0% exempt including fresh produce, milk, medical services, and education. GST Council confirmed no slab changes for 2026-27.
Intra-state (within same state): GST splits equally — CGST to central government, SGST to state government. 18% GST = 9% CGST + 9% SGST. Inter-state: IGST at full rate collected by central government and distributed to destination state.
GST is on the actual transaction value (selling price after discount). If a ₹1,000 item sells at ₹800 with 18% GST, the GST is ₹144 (18% of ₹800), not ₹180 (18% of MRP).