GST Calculator Online Free
Add GST to a base price or remove it from a tax-inclusive amount. See CGST, SGST and IGST breakdown. Works for all Indian GST slabs and global VAT rates.
GST Calculator
Add or remove GST at any rate, with the CGST and SGST split for intra-state supply and IGST for inter-state.
Rates shown are the standard Indian GST slabs. CGST and SGST each take half the rate on intra-state supply, IGST takes the full rate on inter-state supply. Cess on demerit goods is not included. Check the current notified rate for your HSN or SAC code before invoicing.
How this GST calculator handles India’s dual tax structure, and the CGST plus SGST split
Goods and Services Tax, GST, replaced a stack of separate central and state taxes in India starting July 2017 under the one nation, one tax reform. This calculator follows India’s specific GST mechanics by default, an 18 percent slab preselected, an Indian Rupee currency default, and an automatic split of the tax amount into its two Indian components when the currency is set to INR. Switch the currency and the tool adapts, still computing the same underlying tax math but without the India specific CGST and SGST labeling.
Three calculation modes
The tool offers three ways to run the numbers, and each uses a distinct formula depending on whether your starting amount already includes tax.
Worked example: a base amount of 1,000 rupees at the 18 percent slab. Add mode gives a tax of 180 rupees and a total of 1,180 rupees. Because CGST and SGST split the tax evenly under India’s intrastate supply rule, that 180 rupees becomes 90 rupees CGST, Central GST, and 90 rupees SGST, State GST. If the same total of 1,180 were entered in Remove mode instead, the tool would divide by 1.18 to recover the original base of exactly 1,000, not 1,180 minus 180, which happens to match here only because the numbers are round.
| GST slab | Typical goods and services |
|---|---|
| 5% | Essential items, household necessities |
| 12% | Processed foods, some services |
| 18% | Most standard goods and services, the tool’s default |
| 28% | Luxury and sin goods |
Currency behavior
INR selected
Shows the CGST and SGST row pair by default, toggleable to a single IGST row via the checkbox, and formats numbers using Indian digit grouping, en-IN locale, so large amounts read as lakhs and crores style groupings rather than Western thousands separators.
Any other currency
The CGST/SGST toggle is hidden and the tool always shows one combined tax row, since the Central-versus-State split is specific to India’s tax law and does not apply to a generic value-added or sales tax rate in another country. The underlying add, remove, and rate math stays identical.
All math runs client side with no data sent anywhere. This tool computes standard percentage based tax math and is meant for estimation and learning, not as a substitute for filing software or a tax professional, actual GST compliance involves invoicing rules, input tax credit, and filing requirements this tool does not cover.
- GST portal, Government of India, the official source for current GST rates, rules, and filing.
- Central Board of Indirect Taxes and Customs publishes the CGST and IGST Acts and rate notifications.
- Investopedia: Goods and Services Tax (GST) for a general explanation of how GST systems work internationally.
Billing tasks this covers
Working out the tax inclusive price to display on an invoice from a quoted pretax cost, reverse calculating the taxable base from a final receipt total, checking that a vendor’s CGST and SGST split adds up correctly on a business expense, comparing how much a purchase costs across different GST slabs, and estimating tax liability before finalizing a quote for a client.
Questions About GST Calculator Online Free
Select Add GST mode, enter your base price (excluding tax), and pick the GST rate. The tool calculates the tax amount and adds it to give you the final price. Formula: Total = Base x (1 + Rate / 100).
Select Remove GST mode and enter the tax-inclusive amount. The tool extracts the base price using the reverse formula: Base = Inclusive Amount / (1 + Rate / 100). This is called reverse GST calculation or GST backward calculation.
CGST (Central GST) and SGST (State GST) apply to intrastate supply, where the buyer and seller are in the same state. The total GST rate is split equally between them. IGST (Integrated GST) applies to interstate supply, where the transaction crosses state lines, and the full rate goes to the central government. Toggle between these modes using the IGST switch in the calculator.
India has five GST slabs: 0% for essential items like raw food and books, 5% for household necessities and public transport, 12% for processed food and mobile phones, 18% for most services and electronics, and 28% for luxury goods and automobiles. All five are available as one-click presets in this GST calculator online free.
Yes. VAT uses the same percentage-based formula as GST. UK VAT is 20%, which is available as a preset. For EU VAT rates like 21% or 23%, use the custom rate field. Switch the currency to GBP or EUR accordingly.
Yes for simple single-rate GST and VAT. The formulas used are the standard ones: GST = Base x Rate / 100, and for reverse calculation Base = Inclusive / (1 + Rate / 100). Results are shown to 2 decimal places. For compound tax structures or special schemes, consult a chartered accountant.
Yes. Each result row has its own Copy button. The Copy Full Summary button copies all values together as plain text, including the mode, rate, CGST or SGST split, total tax, and final amount. You can paste this directly into an invoice, spreadsheet, or message.
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