GST Calculator
Add GST to a price or extract it from a GST-inclusive price, with the CGST/SGST split for intra-state and IGST for inter-state supplies.
Enter the amount before GST to calculate the total including GST.
Presets are the main GST slabs in force from 22 September 2025. Use Custom for any other rate. Confirm the rate for your goods or service on the CBIC GST portal (cbic-gst.gov.in) or with a tax professional.
About the GST Calculator
Choose Add GST to work forward from a price before tax, or Remove GST to work back from a price that already includes it. Enter the amount, pick a rate, and you get the base amount, the GST and the total, together with the split for both kinds of supply: CGST and SGST at half the rate each for a sale within one state, or IGST at the full rate for a sale from one state to another.
Adding GST is straightforward: 18% on ₹1,000 is ₹180, for a total of ₹1,180 (CGST ₹90 + SGST ₹90, or IGST ₹180). Removing GST works from the inclusive price: GST = price − price ÷ (1 + rate ÷ 100). So ₹1,180 including 18% GST contains ₹180 of tax on a base of ₹1,000. A common mistake is to take 18% of ₹1,180, which gives ₹212.40 and overstates the tax.
The rate buttons cover 0%, 3%, 5%, 18% and 40%, the main slabs after the GST rate changes that took effect on 22 September 2025, when most goods and services moved to 5% or 18% and a 40% rate was introduced for a short list of luxury and "sin" goods. Use Custom for any other rate, such as 0.25%, or the old 12% and 28% slabs when checking earlier invoices. The calculator does arithmetic only and doesn't know which rate applies to your goods or service, so confirm the rate on the official CBIC GST portal (cbic-gst.gov.in) or with a tax professional. When the figures are ready, the Invoice Generator can apply a tax rate to an invoice.
How to use the GST Calculator
- 1
Choose Add GST or Remove GST
Add GST if your amount is before tax; Remove GST if it already includes tax.
- 2
Enter the amount
Type the amount in rupees. The label shows whether it should exclude or include GST.
- 3
Pick the GST rate
Click 0%, 3%, 5%, 18% or 40%, or click Custom and type any rate, including decimals.
- 4
Read the breakdown
See the base amount, GST and total, the CGST and SGST split, the IGST figure and a summary table. Reset clears the amount and custom rate.
What it can do
Both directions
Add GST to a net price, or back-calculate the base price and tax from a GST-inclusive price.
CGST, SGST and IGST
Shows the intra-state split (half the rate each) and the inter-state IGST amount side by side.
Current slabs plus custom rates
Presets for 0%, 3%, 5%, 18% and 40%, and a Custom box for any other rate such as 0.25%, 12% or 28%.
Paisa precision
All amounts are shown to two decimal places in Indian number format.
Limitations
- It does not tell you which rate applies to a product or service, and there is no HSN or SAC code lookup.
- Compensation cess, TDS, TCS, reverse charge and input tax credit are not calculated.
- Each figure is rounded to the paisa, so CGST plus SGST can differ from the GST total by ₹0.01. Invoices may also round per item or to the nearest rupee.
- The CGST/SGST/IGST split is specific to Indian GST, and amounts are always shown in rupees.
- It is an arithmetic aid, not tax advice.
Privacy
The amounts you enter are calculated in your browser and are not sent to FlexyPdf's servers.
Frequently asked questions
How do I find the GST included in a price?
Choose Remove GST, enter the inclusive price and pick the rate. Behind the scenes, the base price is the inclusive price divided by (1 + rate ÷ 100). For ₹1,050 including 5% GST, the base is ₹1,000 and the GST is ₹50.
When does CGST + SGST apply, and when IGST?
As a general rule, a supply within one state attracts CGST and SGST (or UTGST in some union territories) at half the rate each, and a supply from one state to another attracts IGST at the full rate. The total tax is the same either way. The place-of-supply rules decide which applies, so check with your accountant for unusual cases.
What GST rates apply after September 2025?
From 22 September 2025, most goods and services fall under 5% or 18%, a 40% rate applies to a short list of luxury and "sin" goods, and lower rates such as 0%, 0.25% and 3% still exist for particular items. This page doesn't list rates for individual items because they depend on exact classification and can change; check the CBIC GST portal or ask a tax professional.
Can I still calculate 12% or 28% GST?
Yes. Click Custom and type 12 or 28. That is useful for checking invoices issued before 22 September 2025, or for any item that still carries a different rate.
Why don't CGST and SGST add up exactly to the GST amount?
Each figure is rounded to the paisa separately. When the GST has an odd number of paise, halving it leaves half a paisa on each side, so the two rounded halves can add up to ₹0.01 more or less than the rounded total.
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