GST Calculator
CalculatorsAdd GST to a price or strip it out of one, with the correct CGST/SGST or IGST split.
The taxable value on the invoice.
GST rate
Applies to a few goods such as tobacco, aerated drinks and some vehicles.
Total including GST
₹1,180.00
GST of ₹180.00 added
taxable value + GST + cess
- Taxable value
- ₹1,000.00
- the amount you entered
- Total GST
- ₹180.00
- taxable value × rate ÷ 100
- CGST (9%)
- ₹90.00
- GST ÷ 2
- SGST (9%)
- ₹90.00
- GST ÷ 2
- Invoice total
- ₹1,180.00
- taxable value + GST + cess
Supply within one state is split equally between central and state GST. Rounded to the nearest paisa.
How this is calculated
Adding GST (amount is exclusive) GST = base x rate / 100 total = base + GST Removing GST (amount is inclusive) base = total x 100 / (100 + rate) GST = total - base Split Intra-state: CGST = SGST = GST / 2 Inter-state: IGST = GST
Read this before you rely on the number
This is an estimate, not tax advice.
The calculator applies whichever rate you pick. Deciding which rate and which place of supply apply to a transaction is a judgement about your goods or services, and that judgement is yours or your accountant's — a correct calculation of the wrong rate is still a wrong invoice. Slab rates change by GST Council notification, so check the date below before relying on this for filing.
Rates taken from
- CBIC — GST goods and services rates · checked 6 September 2026
Report an error in this tool
How it works
GST works in two directions, and which one you need depends on the figure you are holding. If you have the price before tax, you are adding GST. If you have the final price the customer paid and need to work backwards to the taxable value for your books, you are removing it.
Removing GST is where most people go wrong. Subtracting 18% from an inclusive price of ₹1,180 gives ₹967.60, which is not the answer. The correct taxable value is ₹1,000, because the ₹180 of tax was calculated on ₹1,000, not on ₹1,180. The reverse formula divides by 118 and multiplies by 100 rather than subtracting a percentage.
The split then depends on where the supply happens. Within a single state, the tax is divided equally between central GST and state GST. Across state lines, it becomes a single integrated GST at the full rate. The total is identical either way — only the allocation between governments changes.
Worked example
An invoice of ₹1,180 including 18% GST, for a customer in the same state
- base = 1180 x 100 / (100 + 18)
- base = 118000 / 118 = 1000
- GST = 1180 - 1000 = 180
- CGST = 180 / 2 = 90
- SGST = 180 / 2 = 90
Taxable value ₹1,000 · CGST ₹90 · SGST ₹90 · Total ₹1,180
How to use it
- Choose Add GST if your amount is before tax, or Remove GST if it already includes tax.
- Enter the amount and pick the applicable slab, or type a custom rate.
- Choose intra-state for a supply within one state, or inter-state for one that crosses state lines.
- Add a compensation cess percentage if the goods attract one — this applies to a small set of items such as tobacco, aerated drinks and certain vehicles.
What this tool does not do
- It applies the rate you choose. It does not look up the correct slab for your product — that depends on the HSN or SAC classification.
- It does not determine place of supply, which decides between CGST/SGST and IGST. You select that yourself.
- It is not tax advice. For anything consequential, check with a chartered accountant.
Frequently asked questions
How do I remove GST from an inclusive amount?
Divide the inclusive amount by (100 + rate) and multiply by 100. For 18% GST on ₹1,180: 1180 x 100 / 118 = ₹1,000 taxable value, with ₹180 of GST. Do not simply subtract 18%, which gives the wrong answer of ₹967.60.
What is the difference between CGST, SGST and IGST?
For a supply within one state, GST is split equally into Central GST and State GST. For a supply between two states, the whole amount is charged as Integrated GST instead. The total tax is the same; only who receives it differs.
What are the current GST slabs in India?
The main slabs are 0%, 5%, 12%, 18% and 28%. There are also special rates of 0.25% for rough diamonds and 3% for gold and other precious metals. Some goods additionally attract a compensation cess.
Which GST rate applies to my product?
That depends on the HSN or SAC code for the specific goods or services. This calculator applies whatever rate you select — determining the correct rate and place of supply is your responsibility or your accountant's.
Is GST calculated on the amount before or after discount?
GST is charged on the taxable value after any discount shown on the invoice. If you offer a discount at the time of sale, apply it first and then calculate GST on the reduced amount.
How is compensation cess calculated?
Cess is charged on the taxable value, in the same way as GST — not on the GST amount. So a product with 28% GST and 12% cess carries 40% of the taxable value in total tax.
Does this handle reverse charge?
The arithmetic is identical under reverse charge — the amounts are the same, but the liability to pay sits with the recipient rather than the supplier. This calculator gives you the figures; your filing determines who pays.
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Last updated 3 September 2026.