How to add or remove GST from a price
GST is charged on the taxable value of a supply, so an exclusive price is simply multiplied by the rate: ₹10,000 at 18% adds ₹1,800 of GST for an invoice total of ₹11,800. Extracting GST from an inclusive price works in reverse: divide by (1 + rate). A consumer price of ₹11,800 at 18% contains a taxable value of ₹11,800 ÷ 1.18 = ₹10,000 and GST of ₹1,800. A common mistake is to take 18% of the inclusive price (₹2,124), which overstates the tax.
Set the toggle to "Inclusive" when you are quoting a final price to customers, reconciling a receipt, or working out how much tax is embedded in an MRP. Set it to "Exclusive" when raising a tax invoice from a base price or a rate contract. The calculator also shows the same amount at every standard slab so you can see the effect of a rate change on your pricing.
GST rate slabs and what falls in each
Rates are set by the GST Council against the HSN or SAC code of the item, not by the industry you are in. Always confirm the code on the supplier's invoice or the CBIC rate schedule; the Council has been consolidating slabs (with a two-rate structure of 5% and 18% announced in September 2025 and a special rate for sin goods), so check the current notified rate for your HSN before printing a rate card.
| Rate | Typical goods and services |
|---|---|
| 0% (nil / exempt) | Fresh fruit and vegetables, milk, unbranded food grains, education, healthcare, residential rent |
| 5% | Packaged food, restaurants (no ITC), economy air travel, transport of goods, life-saving drugs, footwear and apparel below thresholds |
| 12% | Processed foods, business-class air travel, some construction materials, works contracts for government |
| 18% | Most services (professional fees, software, telecom), electronics, cosmetics, capital goods, financial services |
| 28% | Luxury and sin goods: cars, tobacco, aerated drinks, air conditioners and large appliances; often with compensation cess |
| 0.25% / 1.5% / 3% | Rough diamonds, cut and polished diamonds, gold and silver jewellery (use the custom rate option) |
CGST and SGST versus IGST
India's GST is a dual tax. When the supplier and the place of supply are in the same state or union territory, the rate is split equally into Central GST and State GST (or UTGST): an 18% supply becomes 9% CGST plus 9% SGST, shown as two lines on the invoice. When the place of supply is in another state, the whole 18% is charged as Integrated GST and the Centre later apportions it to the destination state.
The total tax is identical either way; what changes is how you use input tax credit. IGST credit can be set off against IGST, then CGST, then SGST. CGST credit cannot be used against SGST and vice versa, so a Panchkula business buying from Delhi vendors and selling in Haryana can end up with unusable IGST unless it plans purchases carefully.
Place of supply follows detailed rules: for goods it is normally where delivery ends, for services the recipient's registered address, and for events, property and transport, the location of the event, property or where the journey begins. Exporters charge zero-rated IGST and claim refunds.
Worked example: a ₹50,000 consulting invoice
A Chandigarh consultant bills a Mohali client ₹50,000 for services (SAC 9983, 18%). Both are in Punjab, so the invoice shows taxable value ₹50,000, CGST 9% ₹4,500, SGST 9% ₹4,500, total ₹59,000. If the client were in Delhi, the invoice would show IGST 18% ₹9,000 and the same ₹59,000 total.
If the consultant had agreed an all-inclusive fee of ₹59,000, the taxable value is ₹59,000 ÷ 1.18 = ₹50,000 and the GST is ₹9,000, exactly the figures above. The client, if registered, pays ₹59,000 but recovers ₹9,000 as input tax credit, so the net cost to the client is ₹50,000; to an unregistered client the tax is a real cost.
Who has to register and charge GST
- Registration is compulsory when aggregate turnover crosses ₹40 lakh for goods (₹20 lakh in special category states) or ₹20 lakh for services (₹10 lakh in special category states). Check the current threshold for your state.
- Inter-state supply of goods, e-commerce sellers and businesses liable for reverse charge must register regardless of turnover.
- Composition scheme: manufacturers and traders up to ₹1.5 crore pay 1% of turnover, restaurants 5%, and service providers up to ₹50 lakh pay 6%; they cannot charge GST on invoices or claim input credit.
- Once registered, file GSTR-1 by the 11th and GSTR-3B by the 20th of the following month (quarterly under QRMP if turnover is up to ₹5 crore), and the annual GSTR-9 by 31 December.
- Late filing costs ₹50 a day (₹20 for nil returns) plus 18% interest on tax paid late.
Invoice checklist so your customer gets input tax credit
- Your GSTIN, the customer's GSTIN, invoice number and date, HSN/SAC code with the applicable rate.
- Taxable value, and the CGST/SGST or IGST amounts as separate lines; never show a single "GST 18%" line on a B2B invoice.
- Place of supply and whether reverse charge applies.
- E-invoicing is mandatory if turnover exceeded ₹5 crore in any year since 2017-18; the IRN and QR code must appear on the invoice.
- Report the invoice in GSTR-1 on time so it appears in the customer's GSTR-2B; credit is only allowed for invoices that show up there.