GST Calculator
Add GST to a base price, or work back from a GST-inclusive amount — with the CGST / SGST or IGST split for your invoice.
Calculate GST
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From 22 September 2025 the main GST rates are 5% and 18%, with 40% for specified goods. 12% and 28% are kept for checking older invoices or any supply still taxed at those rates. Type any other rate in the custom box.
Total incl. GST
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Taxable value
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GST amount
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Same amount at every rate
How this calculator works
- Add GST (amount excludes GST): GST = amount × rate ÷ 100; total = amount + GST.
- Extract GST (amount includes GST): taxable value = amount × 100 ÷ (100 + rate); GST = amount − taxable value.
- Within the state: GST is split equally into CGST and SGST/UTGST. Inter-state: the whole GST is IGST. Whether a supply is intra- or inter-state depends on the place of supply rules — choose accordingly.
- Amounts are shown to the paisa. On an invoice each tax may be rounded separately, so totals can differ by a paisa.
- Picking a rate here does not mean that rate applies to your goods or services. Confirm the rate for the HSN/SAC, and any exemption, cess or special scheme, before invoicing.
Worked example
Add GST: ₹10,000 at 18%, within the state.GST = 10,000 × 18% = ₹1,800 → CGST 9% ₹900 + SGST 9% ₹900.
Invoice total = ₹11,800.
Extract GST: ₹11,800 including 18%.
Taxable value = 11,800 × 100 ÷ 118 = ₹10,000; GST = ₹1,800.