Enter an amount and the GST rate — this calculator instantly shows the tax amount and the price with or without GST.
Add GST to a base price, or extract the GST already included in a final price.
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Price with GST
CGST and SGST are shown split equally for intra-state supply (each half of the total GST rate). For inter-state supply, the full amount is charged as IGST instead.
GST is a percentage tax added on top of the base price of goods or services. When you're adding GST, it's applied straightforwardly on the amount. When a final price already includes GST, extracting it requires dividing by (1 + rate/100), not just subtracting the percentage — otherwise you'll get the wrong base price.
Either the base price, or a final price that already includes GST.
Choose the applicable slab — 5%, 12%, 18%, or 28%.
GST amount, CGST/SGST split, and final price.
The GST formula
Adding GST: Final price = amount × (1 + GST% ÷ 100)
Removing GST: Base price = amount ÷ (1 + GST% ÷ 100)
For intra-state sales, GST is split equally: CGST = SGST = GST% ÷ 2.
A worked example
A ₹1,000 base price with 18% GST added:
| Base price | ₹1,000 |
| GST amount (18%) | ₹180 |
| CGST (9%) | ₹90 |
| SGST (9%) | ₹90 |
| Final price | ₹1,180 |
Now reverse it: extracting GST from a ₹1,180 final price gives back exactly ₹1,000 as the base price — not ₹968 (which is what a plain 18% subtraction would wrongly give).
Common GST slabs in India
5%
Essential goods, transport
12%
Processed food, business class
18%
Most goods and services
28%
Luxury and sin goods
Because the 18% was calculated on the base price, not the final price. Subtracting 18% of the final price removes too much — you need to divide by 1.18 instead to get back the correct base price.
CGST and SGST apply to sales within the same state, splitting the GST rate equally between the central and state governments. IGST applies to inter-state sales, with the full GST rate going to the central government and then apportioned to the destination state.
No — India uses multiple GST slabs (mainly 5%, 12%, 18%, and 28%) depending on the category of goods or services, with some items like fresh produce exempted entirely.
GST replaced VAT and several other indirect taxes in India. Conceptually both are consumption taxes, but GST unifies what used to be separate central and state-level taxes into one structure.
Use this calculator to quickly confirm the GST breakdown before you finalize an invoice.