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GST calculator
Add GST to a price, or find the taxable value inside a GST-inclusive price, with the CGST and SGST or IGST split shown. Free, no sign-up, and nothing you type leaves your browser.
GST rate
Supply
How it works
- 1Type the amountUse the keypad or your keyboard, and choose Add GST or Remove GST.
- 2Pick the rate and supplyRate chips from 0.25% to 40%, within the state or to another state.
- 3Copy or share the splitTaxable value, CGST/SGST or IGST and the total, ready to paste.
Runs in your browser. Nothing you type or upload is sent to Cashflow OS.
How to use the calculator
- Enter the amount.
- Choose Add GST if the amount is before tax, or Remove GST if the amount already includes tax (an MRP or a rate quoted "inclusive").
- Pick the rate: 0.25%, 3%, 5%, 12%, 18%, 28%, or type a custom rate such as 40%.
- Choose Within the state (CGST + SGST) or Another state (IGST).
- Read the taxable value, the tax and the total, and copy the result if you need to paste it into a quotation or a message.
The two formulas
Adding GST to a price before tax: GST = amount × rate ÷ 100, and total = amount + GST.
Removing GST from a price that already includes it: taxable value = amount × 100 ÷ (100 + rate), and GST = amount − taxable value.
A common mistake is to remove GST by simply taking 18% off the inclusive price. That gives the wrong answer, because the 18% was charged on the smaller taxable value, not on the total.
A worked example
You sell 10 fans at ₹1,250 each to a shop in your own state, at 18% GST.
| Line | Amount |
|---|---|
| Taxable value (10 × ₹1,250) | ₹12,500 |
| CGST 9% | ₹1,125 |
| SGST 9% | ₹1,125 |
| Total | ₹14,750 |
If the same fans go to a buyer in another state, the tax is one line: IGST 18% = ₹2,250, and the total is still ₹14,750. Going the other way, a customer who pays ₹14,750 "all inclusive" at 18% has paid ₹12,500 for the goods and ₹2,250 as tax.
CGST and SGST, or IGST?
The split depends on the place of supply, not on where the payment comes from. If the supplier's state and the place of supply are the same, the tax is shared equally between CGST and SGST (UTGST in some union territories). If they are different, the whole tax is IGST. The total tax is the same either way. Read more in IGST vs CGST and SGST.
Check the current rate before you bill
GST rates are set by notification and do change. The rate structure was rationalised in 2025: many goods moved to 5% or 18%, a 40% rate applies to some items, and the 12% and 28% slabs no longer apply to most goods. This calculator keeps the older rates and a custom field so you can work out any figure, but the rate on your invoice must be the one in force for the item's HSN code on the date of supply. Check it on cbic-gst.gov.in or with your CA, and see HSN and SAC codes explained.
This is general information, not tax advice.
Questions people ask
How do I calculate GST from a total amount?
Divide the total by (100 + rate) and multiply by 100 to get the taxable value. For ₹11,800 at 18%, the taxable value is ₹10,000 and the GST is ₹1,800.
Is CGST plus SGST more than IGST?
No. CGST and SGST are each half of the rate, so 9% + 9% equals IGST at 18%. Only who receives the tax changes.
Should GST be rounded per item or on the total?
Many businesses work out tax per line and round the invoice total to the nearest rupee as a round-off line. Whatever you choose, use it the same way on every invoice.
Can I use this for services?
Yes. The arithmetic is the same for goods and services; only the code (SAC instead of HSN) and the applicable rate differ.
Why is there a 0.25% and 3% option?
These rates apply to a few specific goods, such as rough precious stones and gold. Check the current notification for your item before using them.
General information for Indian businesses, not tax or legal advice. GST rates and rules change by notification — check cbic-gst.gov.in or ask your CA before you rely on a figure.
