GST Calculator — Add or Remove GST Instantly
Add GST to a base price or extract GST from an inclusive amount — with instant CGST/SGST or IGST split at every official slab rate.
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How to calculate GST from a base price
Multiply the base amount by the rate percentage: GST = base × rate ÷ 100, and total = base + GST. At 18% on ₹1,000, GST is ₹180 and the invoice total is ₹1,180. Choose Add GST mode, enter the base amount, tap a rate chip, and the total and tax split appear instantly.
How to remove GST from an inclusive amount
Divide the inclusive total by one plus the rate: base = total ÷ (1 + rate ÷ 100). From ₹1,180 at 18%, the base is ₹1,000 and the GST inside is ₹180. Subtracting 18% of ₹1,180 directly gives the wrong answer — the reverse formula is the correct one, and Remove GST mode applies it for you.
CGST + SGST or IGST — which applies?
If the supplier and the place of supply are in the same state, the tax splits equally into CGST and SGST. If they are in different states — or the supply is an import or to an SEZ — the entire tax is levied as IGST. The total tax amount is identical either way; only the invoice breakup changes.
GST slab rates in India
The standard slabs are 0.25%, 3%, 5%, 12%, 18% and 28%, set by the GST Council and notified through the CBIC rate schedule. The applicable rate depends on the HSN code for goods or SAC code for services. Use the custom rate field for composite or cess-adjusted effective rates.
Add GST or Remove GST From Any Amount — Both Directions
Goods and Services Tax calculations run in two directions and this calculator handles both. Add GST mode takes a base price — the exclusive amount on a quotation or price list — and computes the tax and final invoice total at your chosen rate. Remove GST mode works backwards: paste any GST-inclusive figure, like a bill total or MRP-style price, and it extracts the original base price and the exact tax component inside it. The reverse calculation uses the correct division formula, base equals total divided by one plus the rate, not a naive percentage subtraction — the mistake that makes most manual reverse-GST math wrong. Results update live as you type, with no signup and no upload.
CGST, SGST and IGST Breakup at Every Slab Rate
Indian GST splits differently depending on where the buyer and seller are. For an intra-state supply, the tax divides equally into Central GST and State GST — an 18% rate becomes 9% CGST plus 9% SGST, and both halves appear on the invoice separately. For an inter-state supply, the full amount is charged as Integrated GST instead. This calculator shows the correct split for either case with one toggle, at every official slab — 0.25%, 3%, 5%, 12%, 18% and 28% — plus a custom rate field for cess-adjusted or special rates. The breakup matches the format GST invoices require, so you can copy the figures straight into billing.
Which GST Rate Applies to Your Goods or Services?
The slab structure covers most of the economy in a few bands: 0.25% applies to rough precious stones, 3% to gold and jewellery, 5% to essentials and many food items, 12% and 18% to the bulk of goods and services including most professional services, and 28% to luxury and sin-category items, some carrying additional cess. Rates are notified by the GST Council and published in the CBIC rate schedule, and they do change — always confirm the current rate for your specific HSN or SAC code before invoicing. This page's slab chips reflect the standard structure as of the verification date shown below the result, and the custom field covers any rate the chips don't.
Frequently asked questions
How do I remove GST from a total amount?
Divide the inclusive amount by one plus the rate as a decimal: base = total ÷ (1 + rate ÷ 100). For ₹1,180 at 18%, base = 1180 ÷ 1.18 = ₹1,000. Remove GST mode does this automatically and shows the tax component separately.
What is the difference between CGST, SGST and IGST?
CGST and SGST apply together on intra-state supplies, each taking half the rate. IGST applies as a single levy on inter-state supplies. The total tax is the same in both cases — only how it is split on the invoice differs.
What are the current GST slab rates in India?
The standard slabs are 0.25%, 3%, 5%, 12%, 18% and 28%. The rate for a specific item depends on its HSN or SAC code as notified by the GST Council. Some items also attract compensation cess on top of the 28% slab.
Is 18% GST split as 9% + 9%?
Yes, for intra-state supplies — 9% CGST plus 9% SGST. For inter-state supplies the same 18% is charged entirely as IGST. This calculator shows the correct split with one toggle.
Can I calculate GST at a custom rate?
Yes. Besides the standard slab chips, a custom rate field accepts any percentage from 0 to 100 — useful for effective rates that include cess or for composition-scheme calculations.
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Data verified: 2026-07-04 · All processing happens in your browser — no files are ever uploaded.