greytHR introduces a free GST calculator for India. Enter your amount and rate, choose to include or exclude GST, and get an instant CGST/SGST or IGST split - no manual math, calculated as you type.
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₹
GST breakdown
Base amount (excl. GST)₹10,000
CGST (9%)₹900
SGST (9%)₹900
IGST (18%)₹1,800
Total GST₹1,800
Total amount (incl. GST)₹11,800
GST added at 18%.
What is GST?
GST (Goods and Services Tax) is India's unified indirect tax on goods and services, replacing VAT, service tax, and excise duty since 1 July 2017. It's a destination-based tax split into CGST, SGST, or IGST depending on where the sale happens - useful to know whether you're pricing a product, raising an invoice, or checking a bill.
GST rate slabs in India
GST is levied across five main slabs, plus two special rates:
Rate
Typical goods & services
0%
Essential items - fresh produce, milk, books
5%
Household necessities, transport, small restaurants
12%
Processed foods, business-class air travel
18%
Most goods and services, IT, telecom
28%
Luxury and "sin" goods - cars, tobacco
0.25% / 3%
Rough diamonds; gold and precious metals
How to calculate GST
To add GST (price excludes GST): GST = (Amount × Rate) ÷ 100 · Total = Amount + GST
To remove GST (price includes GST): Base = Amount × 100 ÷ (100 + Rate) · GST = Amount − Base
For a sale within the same state, the GST is shared equally between the Centre and the State - half as CGST and half as SGST. For a sale across states, a single IGST applies at the full rate.
The 4 types of GST in India
GST in India isn't a single tax - it's split into four components depending on where the sale happens:
Type
Applies to
Collected by
CGST
Sales within the same state (half the rate)
Central Government
SGST
Sales within the same state (other half the rate)
State Government
IGST
Sales between two different states (full rate)
Central Government, then apportioned to the destination state
UTGST
Sales within a Union Territory without its own legislature (e.g. Chandigarh, Lakshadweep) - charged instead of SGST
Union Territory administration
Example
On a ₹10,000 product at 18% GST (intra-state): GST = ₹1,800, split as ₹900 CGST + ₹900 SGST, making the total ₹11,800.
How to use this GST calculator
Enter the amount.
Choose Add GST (price is before tax) or Remove GST (price already includes tax).
Pick the GST rate and whether the supply is intra- or inter-state.
The base price, CGST/SGST (or IGST) and total update instantly.
GST calculator FAQs
How is GST calculated in India?
To add GST, multiply the base amount by the rate: GST = (Amount × Rate) ÷ 100, and Total = Amount + GST. To remove GST from a GST-inclusive price, Base = Amount × 100 ÷ (100 + Rate), and GST = Amount − Base.
What is the difference between CGST, SGST, IGST and UTGST?
For sales within the same state, GST is split equally into CGST (Central) and SGST (State). For inter-state sales, a single IGST is charged at the full rate instead. UTGST replaces SGST for sales within a Union Territory that has no legislature of its own, like Chandigarh or Lakshadweep.
What are the GST rate slabs in India?
India has five main slabs - 0%, 5%, 12%, 18% and 28% - plus special rates of 0.25% and 3% for items like rough diamonds and gold.
How do I remove GST from a total amount?
Use the reverse formula: Base = inclusive amount × 100 ÷ (100 + rate). The GST component is the inclusive amount minus the base. Select "Remove GST" above and the calculator does it for you.
What is a reverse GST calculator?
A reverse GST calculator works backward from a GST-inclusive price to find the original base amount and the GST hidden inside it - useful when a bill or invoice only shows the final total. Select "Remove GST" above and enter the inclusive amount to use this calculator as a reverse GST calculator.
What is the difference between GST inclusive and exclusive amount?
A GST-exclusive amount is the price before tax is added - choose "Add GST" for this. A GST-inclusive amount already has GST built into it - choose "Remove GST" to work out the tax and base price hidden inside that total.