What are the GST slabs in India in 2026?

India uses five primary GST rates: 0%, 5%, 12%, 18%, and 28%. A few special items use 3% (gold) and 0.25% (rough precious stones). The applicable rate is determined by the HSN code for goods or SAC code for services.

How is CGST + SGST different from IGST?

CGST and SGST are charged together on intra-state supplies (supplier and buyer in the same state). Each is half of the total GST. IGST is charged on inter-state supplies, imports, and exports the full GST amount is paid as IGST, and the Centre later distributes the state portion to the destination state.

What is the difference between GST inclusive and exclusive?

An amount that is "exclusive of GST" is the taxable value, and GST is added on top. An amount that is "inclusive of GST" already contains the tax to find the taxable value you divide by (1 + rate/100). Use the exclusive mode when you have a price list net of tax, and inclusive mode when you have a final invoice total and need to extract the tax.

What is the formula for reverse GST calculation?

Reverse GST (extracting GST from an inclusive amount) uses this formula: Taxable value = Gross amount ÷ (1 + GST rate / 100). The GST amount is then the difference between the gross amount and the taxable value. Switch the calculator to "Inclusive of GST" to run this automatically.

Does this GST calculator work for both goods and services?

Yes. The rate slabs apply to both goods (HSN codes) and services (SAC codes). Pick the rate that matches the HSN or SAC code on your invoice and the math is identical.

Is the calculation right when GST is charged on a discounted price?

Yes, as long as the discount is shown on the invoice and reduces the taxable value. Enter the post-discount amount as the exclusive value. GST is always computed on the actual transaction value after trade discounts.

Does the calculator handle the GST cess (e.g. on tobacco or cars)?

Not in this version. GST cess is levied on top of the 28% rate for specific demerit goods (tobacco, aerated drinks, luxury cars) at varying rates by HSN. Cess values vary widely, so we recommend cross-checking the latest cess notification for those specific items.

Can I use this for export invoices?

Exports are zero-rated under GST. You can model an export by selecting 0%, or by using inter-state and 0% if shipping under LUT. If you export with tax (claiming refund), select inter-state and the applicable IGST rate.

Is the calculator GSTR-1 / GSTR-3B compliant?

The math matches what GSTR-1 and GSTR-3B expect. To file a return you still need invoice-level data, GSTIN, HSN/SAC, place of supply, and so on. Use the calculator for quick checks; use FireAI for live GSTR-1 / 3B / 2B dashboards built from your Tally data.

Does the data I enter leave my browser?

No. Every calculation runs locally on your device. There is no API call, no server log, and no analytics on the amounts you type. We track only that the page was visited and that buttons were clicked, not the numbers in any field.

How accurate is the GST math?

The math is exact to the precision of JavaScript floating-point arithmetic and rounded for display to two decimal places. For invoice issuance and return filing, round CGST, SGST, and IGST to the nearest paisa as per rule 34A of the CGST Rules.

What about Reverse Charge Mechanism (RCM) supplies?

For RCM, the recipient pays GST instead of the supplier. The math is the same enter the value and the applicable rate, and the calculator gives you the GST amount you need to deposit. You then claim the same as ITC in the next return (subject to eligibility).

Finance & GST · Free tool

GST Calculator CGST, SGST & IGST (Free)

Calculate GST on any invoice value at 0%, 5%, 12%, 18%, 28%, or a custom rate. Switch between intra-state (CGST + SGST) and inter-state (IGST) supply, and between exclusive and inclusive amounts. No signup, no data sent to a server every calculation runs in your browser.

Connect Tally → live GST dashboards

GST rate slabs in India (2026)

India uses a four-tier GST rate structure plus a 0% slab for essential goods. The rate that applies to a product or service is determined by its HSN/SAC code.

Rate	Typical goods & services	Intra-state split
0%	Unbranded food grains, fresh produce, milk, books, education, healthcare	0% + 0%
5%	Branded packaged food, footwear < ₹1,000, economy travel, life-saving drugs	CGST 2.5% + SGST 2.5%
12%	Processed food, business-class travel, mobile phones, ayurveda	CGST 6% + SGST 6%
18%	Most services (SaaS, consulting, telecom), apparel > ₹1,000, financial services	CGST 9% + SGST 9%
28%	Luxury cars, tobacco, aerated drinks, premium hotels	CGST 14% + SGST 14%

How to calculate GST

The formulas the calculator runs on are simple, and identical to those used by every GST return preparation utility:

When the amount is exclusive of GST

GST amount = Taxable value × (GST rate / 100)
Invoice total = Taxable value + GST amount

When the amount is inclusive of GST

Taxable value = Gross amount ÷ (1 + GST rate / 100)
GST amount = Gross amount − Taxable value

Intra-state vs inter-state

Intra-state (supplier and recipient in same state): GST is split equally as CGST + SGST.
Inter-state (different states, or imports/exports): the full GST is charged as IGST.

Already filed late? Calculate the damage

If a return was filed after the due date, late fee at ₹50/day (₹20/day for nil returns) plus interest at 18% p.a. on unpaid tax applies. Use the GST Late Fee & Interest Calculator to work out the exact amount before you file.

From calculator to live GST dashboards

A calculator handles one invoice at a time. For monthly returns, you need to roll up GSTR-1 outward supplies, GSTR-3B summaries, and 2A/2B reconciliation across hundreds or thousands of vouchers. That’s what FireAI does it reads your Tally data directly and builds a live GST compliance dashboard with auto-reconciliation.

Get this calculator running on your live data

Connect Tally → live GST dashboards

Frequently asked questions

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