The CGST and SGST split shown applies to an intra-state supply. For an inter-state supply the same total is charged as a single IGST.
Total price
₹11,800
- GST at 18%
- ₹1,800
- CGST + SGST
- ₹900 + ₹900
Adding versus removing GST
These are not the same sum, and mixing them up is the most common error on GST calculators. Adding GST to ₹10,000 at 18% gives ₹11,800. Removing GST from ₹11,800 gives ₹10,000 back — but removing 18% of ₹11,800 gives ₹9,676, which is wrong.
The correct reverse formula divides rather than subtracts: net = gross ÷ (1 + rate). This calculator makes you say which one you mean rather than guessing.
CGST, SGST and IGST
On a supply within a state, the total GST is split evenly between the centre (CGST) and the state (SGST) — 18% is 9% plus 9%. On a supply between states, the same total is charged once as IGST and later apportioned. The rate the customer pays is identical either way; only the labels on the invoice change.
Common questions
The rate depends on the HSN or SAC code of what is being supplied, and the slabs are revised by the GST Council from time to time. The CBIC rate finder linked below is the authoritative source — this calculator does the arithmetic once you know the rate.
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