GST Calculator
Add or remove GST on any amount
Reviewed by the PaisaTools Editorial Team · Last reviewed September 2026 · Applicable to FY 2026-27 (AY 2027-28)
How to use: Pick if your amount is before or after GST, type the amount, and tap a rate.
Example₹10,000 + 18% GST = ₹11,800
We'll add GST on top and show the final price
Final price (with GST)
₹11,800
Base amount
₹10,000
GST (18%)
₹1,800
Breakdown
- Base amount
- ₹10,000
- CGST (9%)
- ₹900
- SGST (9%)
- ₹900
- Total GST (18%)
- ₹1,800
- Total amount
- ₹11,800
CGST + SGST applies to intra-state sales. For inter-state, it's a single IGST of 18% (same total).
GST (Goods and Services Tax) is India's indirect tax. This tool works both ways:
Add GST — you have a pre-tax price and want the final payable: total = base × (1 + rate).
Remove GST — you have a tax-inclusive total (say off an invoice) and want the base it was built from: base = total ÷ (1 + rate).
The breakdown shows the CGST/SGST split for intra-state billing. Before you bill a client, you can also validate their GSTIN.
GST is applied at the slab you select (0/5/18/40% under GST 2.0, 3% on gold, or a custom rate) and split equally into CGST + SGST for intra-state supply, or charged as IGST for inter-state supply — per the framework of the Central and State GST Acts. The rate slabs are set by the GST Council and revised periodically, so confirm the current notified rate (and HSN code) for a specific item before invoicing.
- The correct rate depends on the item's HSN/SAC code — choose the right slab.
- CGST+SGST vs IGST depends on the place of supply.
- How do I add GST to an amount?
- Multiply the base amount by (1 + rate/100). For ₹10,000 at 18%: 10,000 × 1.18 = ₹11,800. The calculator does this in 'Add GST' mode.
- How do I remove GST from a total?
- Divide the GST-inclusive amount by (1 + rate/100) to get the base. For ₹11,800 at 18%: 11,800 / 1.18 = ₹10,000. Use 'Remove GST' mode.
- What is CGST and SGST?
- For sales within the same state, GST is split equally into CGST (central) and SGST (state). 18% becomes 9% CGST + 9% SGST. The total is unchanged.
- When is IGST charged instead?
- For inter-state sales, a single IGST is charged at the full rate (e.g. 18%) instead of the CGST+SGST split. The amount you pay is the same.
- What are the common GST slabs in India?
- After the GST 2.0 reform (effective 22 September 2025) the main slabs are 0%, 5%, 18% and 40% — the old 12% and 28% slabs were removed. A special 3% applies to gold/jewellery. Most goods and services fall under 18%, with 40% reserved for luxury and 'sin' goods.
Related guides
- GST Rates 2026: the full slab list (0, 5, 18, 40%)Every slab after the 22 Sep 2025 reform: what moved out of the old 12% and 28% bands, where gold sits, and how CGST and SGST split.
- GST late fee and interest: what a late return really costsWhat a late GSTR-3B or GSTR-1 actually costs you — the daily fee, the interest on top, and the cap that limits both.
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