GST Calculator
Add GST on top of a price, or work out the base price and GST hidden inside a GST-inclusive amount.
Calculation type
Enter the base amount — GST will be added on top.
Base amount
₹1,000
GST amount
₹180
Total amount
₹1,180
CGST
₹90
For intra-state supply
SGST
₹90
For intra-state supply
For inter-state supply, the full GST amount is charged as IGST instead of a CGST + SGST split.
How to use the GST Calculator
- Choose Add GST if your amount excludes tax, or Remove GST if it already includes tax.
- Enter the amount.
- Enter the GST rate, or pick a common slab rate (5%, 12%, 18%, 28%).
- See the base amount, GST amount, total, and the CGST/SGST split instantly.
What is a GST calculator?
A GST calculator works out the Goods and Services Tax on a price, either by adding tax to a tax-free amount or by extracting the tax already built into a GST-inclusive price. It also splits that tax into CGST and SGST, matching how GST is typically shown on an Indian invoice for a sale within the same state.
How the calculation works
Adding GST simply multiplies the base amount by the tax rate and adds it on top. Removing GST works backward: since the inclusive amount already equals the base plus tax, dividing it by (1 + rate) recovers the original base amount, and the difference between the two is the GST.
Formula
- Adding GST:
GST amount = Base × (rate ÷ 100) - Removing GST:
Base = Total / (1 + rate / 100)
Worked example
A product priced at ₹1,000 (before GST) at 18% GST costs ₹1,180 after tax — made up of ₹90 CGST and ₹90 SGST for an intra-state sale.
Understanding your result
- Base amount is the price before tax.
- GST amount is the total tax charged.
- CGST + SGST is the GST amount split equally, as shown on an intra-state invoice.
- Total amount is what the customer actually pays.
Factors that affect the result
The result depends entirely on the GST rate that applies to the specific goods or service, and on whether the amount you enter already includes tax or not. Getting either of these wrong is the most common source of an incorrect result.
Common uses
Small business owners use this to quickly quote GST-inclusive prices to customers, freelancers use it to work out GST on an invoice, and shoppers use it to check how much tax is included in a receipt or price tag.
Important notes & limitations
This calculator shows a standard CGST/SGST split, which applies to sales within the same state. For inter-state sales, the full amount is charged as IGST instead. Always confirm the applicable GST rate for your specific goods or services, as rates vary by category.
Frequently asked questions
What is a GST calculator used for?
It's used to quickly add or remove Goods and Services Tax from a price, so you can quote GST-inclusive prices, check an invoice, or work out how much tax is embedded in a receipt.
What GST rates are available?
Common slab rates of 5%, 12%, 18% and 28% are provided as quick presets, and you can enter any custom rate.
What's the difference between CGST, SGST and IGST?
For sales within the same state, GST is split equally between CGST (central) and SGST (state). For sales between different states, the full amount is charged as IGST (integrated GST) instead.
How do I know if my amount already includes GST?
If you're quoting a price to a customer and haven't added tax yet, use Add GST. If you have a final invoice or receipt total that already includes tax, use Remove GST to see the breakdown.
Does this work for any product or service category?
Yes, as long as you know the correct GST rate for that category — the calculator itself works the same way regardless of what's being taxed.
Is the CGST/SGST split always exactly equal?
Yes, for intra-state supply the total GST amount is always split 50/50 between CGST and SGST under the current GST structure.
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