How do I add GST to a price?

Select Add GST mode, enter your base price excluding tax, and pick the GST rate. Formula: Total = Base x (1 + Rate / 100).

How do I find the original price from a GST-inclusive amount?

Select Remove GST mode and enter the tax-inclusive amount. Formula: Base = Inclusive Amount / (1 + Rate / 100).

What is the difference between CGST, SGST and IGST?

CGST and SGST apply to intrastate supply and split the GST rate equally. IGST applies to interstate supply at the full rate. Toggle between them using the IGST switch.

What are the standard Indian GST rates?

Since GST 2.0 on 22 September 2025 the main slabs are 0%, 5% and 18%, plus 40% for luxury and sin goods. The 12% and 28% rates now cover only a few items. All of these, plus 0.25% and 3%, are presets in this calculator.

Can I use this as a VAT calculator?

Yes. VAT uses the same percentage formula. Enter 20% for UK VAT, or any EU rate, in the custom rate field.

Is the GST calculation formula accurate?

Yes for simple single-rate GST and VAT. GST = Base x Rate / 100 for adding, Base = Inclusive / (1 + Rate / 100) for removal. Results shown to 2 decimal places.

Can I copy the results to use in an invoice?

Yes. Each result row has a Copy button. Copy Full Summary copies everything as plain text including CGST, SGST, total tax and final amount.

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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.

Add GST Remove GST CGST + SGST split IGST Custom rate VAT

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GST Calculator

Add or remove GST at any rate, with the CGST and SGST split for intra-state supply and IGST for inter-state.

What do you want to do

Base Amount (excl. GST)

₹

The figure on your invoice.

Currency Only INR shows the CGST and SGST split.

Custom rate

Overrides the slab buttons below.

GST rate slab

Inter-state supply (IGST) Tick when buyer and seller are in different states. Untick for CGST plus SGST.

Base Amount (excl. GST) ₹0.00

CGST 9% ₹0.00

SGST 9% ₹0.00

Total GST ₹0.00

Total (incl. GST) ₹0.00

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.

About This Tool

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.

Add GST You enter a base amount that excludes tax. GST equals base times the rate divided by 100, and the total is base plus that tax amount. This is the mode for pricing a product before tax when you know the pre-tax cost.

Remove GST You enter a GST-inclusive amount, a price that already has tax baked in. The base amount is the inclusive total divided by one plus the rate over 100, not a simple subtraction, since the tax itself was calculated on the base, not on the inclusive total.

Tax amount only Uses the same base times rate over 100 formula as Add GST, but the display only shows the tax figure itself rather than a running total, useful when you just need the tax line for a ledger entry.

// add mode, adapted from the tool source base = amt; tax = amt * rate / 100; total = amt + tax; // remove mode, extracting base from an inclusive price total = amt; base = amt / (1 + rate / 100); tax = total - base; // CGST/SGST split for intra-state supply in India cgst = tax / 2; sgst = tax / 2;

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%	Essentials, most packaged food and medicines
12%	Only a short list of items since 22 September 2025
18%	Most standard goods and services, the tool's default
28%	Only a short list of items since 22 September 2025
40%	Luxury and sin goods under GST 2.0

CGST and SGST versus IGST is about where the transaction happens, not the tax rate. India's GST law splits tax collection based on whether a sale is intra-state or inter-state. A sale within one state splits the tax evenly between the Central government, CGST, and that state's government, SGST, each getting half the total rate. A sale across state lines instead charges Integrated GST, IGST, the full rate collected by the central government and later apportioned to the destination state. The rate you pay is the same either way, it is only the accounting split that changes. This tool lets you toggle the IGST checkbox to switch between the two views for the same rate.

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.

Rate slabs from 0% to 40% Custom rate input Copy summary to clipboard Indian digit grouping for INR

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.

Common Questions

Questions About the GST Calculator

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.

Since GST 2.0 took effect on 22 September 2025, the main slabs are 0%, 5% and 18%, with a 40% slab for luxury and sin goods. The old 12% and 28% rates now cover only a short list of items, and special rates of 0.25% and 3% apply to precious stones and gold. All of these are one-click presets in this free GST calculator, and the custom rate field covers anything else.

Yes. VAT uses the same percentage-based formula as GST. Enter 20% in the custom rate field for UK VAT, or any EU rate such as 21% or 23%. 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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