What Is GST?
GST (Goods and Services Tax) is a unified indirect tax levied on the supply of goods and services across India. Implemented on July 1, 2017, it replaced a fragmented system of multiple indirect taxes including VAT, Service Tax, Central Excise Duty, CST, and Octroi with a single, destination-based tax structure.
GST is collected through the supply chain, while input tax credit may be available to eligible registered businesses subject to the applicable rules and documentation. This calculator handles arithmetic only; it does not determine registration, classification, place of supply, input-tax-credit eligibility, reverse charge, or return-filing treatment.
Common GST Rate Shortcuts
The quick buttons cover commonly used headline rates. They are not a product or service classification guide. The legally applicable rate can depend on the HSN or SAC classification, conditions in the relevant notification, exemptions, and later amendments. Use the custom-rate field when the notified rate is not one of these shortcuts.
| Shortcut | Calculator Treatment | Before Using It |
|---|---|---|
| 0% | No GST is added or extracted | Confirm whether the supply is nil-rated, exempt, non-taxable, or zero-rated |
| 5% | Calculates GST at 5% | Confirm the HSN/SAC entry and any conditions |
| 12% | Calculates GST at 12% | Confirm the HSN/SAC entry and any conditions |
| 18% | Calculates GST at 18% | Confirm the HSN/SAC entry and any conditions |
| 28% | Calculates GST at 28% | Check whether compensation cess or another condition also applies |
CGST vs SGST vs IGST
| Tax | Full Form | Collected By | When Applied | Rate |
|---|---|---|---|---|
| CGST | Central GST | Central Government | Intrastate | Half of GST rate |
| SGST | State GST | State Government | Intrastate | Half of GST rate |
| IGST | Integrated GST | Central Government | Interstate | Full GST rate |
For a typical intrastate scenario, the calculator splits the selected GST rate equally between CGST and SGST. For an interstate scenario, it shows the full amount as IGST. Actual treatment depends on place-of-supply rules; UTGST may apply in relevant Union Territory cases.
GST Calculation Formulas
Adding GST to a Base Amount
GST Amount = Base Amount × GST Rate ÷ 100Final Amount = Base Amount + GST AmountExample: ₹10,000 × 18% = ₹1,800 GST → Total ₹11,800
Removing GST from Inclusive Amount
Taxable Value = Total ÷ (1 + GST Rate ÷ 100)GST Amount = Total − Taxable ValueExample: ₹11,800 ÷ 1.18 = ₹10,000 base → GST ₹1,800
Continue Your Business Calculations
Apply a price reduction before tax with the Discount & Final Price Calculator, or evaluate cost, selling price, markup, and margin with the Profit Margin Calculator.
When the figures are ready, prepare a customer document with the Quotation & Estimate Generator or the Invoice Generator.
Verify the Applicable GST Rate
Check the latest official classification and amendments in the GST Council rate notifications. For transaction-value rules, refer to Section 15 of the CGST Act on the CBIC website.
Frequently Asked Questions
Disclaimer: This calculator performs arithmetic estimates only. It does not determine the correct HSN/SAC classification, place of supply, exemption, reverse charge, input tax credit, compensation cess, invoicing requirement, or return treatment. GST rates and rules can change; verify the applicable notification and seek qualified advice before issuing an invoice or filing a return.