Rules checked on 17-10-2026
How to use the GST calculator
- Choose whether your price is before GST (you want to add GST) or including GST (you want to find the GST inside it).
- Choose within the state for CGST + SGST, or to another state for IGST. The place of supply decides this, not the delivery address.
- Tap a rate. It applies to every row; change one row's rate in the table if your bill mixes rates.
- Type the quantity and price. Press Enter to move to the next box. Add rows for more items, and cess if your item still carries it.
- Read the taxable value, CGST, SGST or IGST, round-off and total. Use Copy result to paste the working into a message or a sheet.
The GST formula
Adding GST: GST = taxable value × rate ÷ 100. Total = taxable value + GST.
Removing GST from an inclusive price: price before GST = inclusive price × 100 ÷ (100 + rate). GST = inclusive price − price before GST.
Within a state the rate is split equally: 18% becomes 9% CGST + 9% SGST (UTGST in a union territory). Between states the full 18% is IGST. The tax is the same; only the head changes.
Worked examples
1. Add 18% GST, sale within the state
10 ceiling fans at ₹1,250 each, sold from Pune to a shop in Nashik. Taxable value = 10 × ₹1,250 = ₹12,500. CGST 9% = ₹1,125 and SGST 9% = ₹1,125. Bill total = ₹14,750.
2. Same bill to another state
The same fans sold to a buyer in Bengaluru: IGST 18% = ₹2,250, total ₹14,750. Your buyer claims the IGST as input tax credit in the same way.
3. Remove GST from an inclusive price
A customer pays ₹1,180 including 18% GST. Price before GST = 1,180 × 100 ÷ 118 = ₹1,000. GST inside the price = ₹180 (₹90 CGST + ₹90 SGST).
4. Paise and round-off
Taxable ₹100.42 at 18%: CGST = 9% of ₹100.42 = ₹9.0378, which rounds to ₹9.04; SGST is rounded on its own to ₹9.04. Total ₹118.50; with round-off on, ₹0.50 is added and the bill is ₹119.
GST rates after 22 September 2025
The GST Council's rate rationalisation (CGST rate notification 9/2025, in force from 22 September 2025) replaced the four main slabs with two, plus a higher rate for a short list of goods.[1] Most goods that were at 12% moved to 5%, and most at 28% moved to 18%. Check your item's rate by its HSN code before you bill.
| GST rate | CGST + SGST | Used for |
|---|---|---|
| 0% | 0% + 0% | Nil-rated and exempt goods |
| 5% | 2.5% + 2.5% | Lower rate: many everyday goods |
| 18% | 9% + 9% | Standard rate: most goods and services |
| 40% | 20% + 20% | A short list of luxury and sin goods |
| 3% | 1.5% + 1.5% | Gold, silver and jewellery |
| 1.5% | 0.75% + 0.75% | Cut and polished diamonds |
| 0.25% | 0.125% + 0.125% | Rough precious and semi-precious stones |
Compensation cess ended on 1 February 2026, when tobacco products and pan masala moved to the 40% rate.[2] The cess box stays in the calculator for bills dated before then. For older bills you can also type 12% or 28% in the Other rate box.
Why our totals match a real invoice
Many calculators work out GST on the bill total. A tax invoice works line by line: each line's taxable value is rounded to paise, CGST and SGST are worked out and rounded separately, and the bill total is the sum of the lines. This calculator uses the same tax engine as Moharbill's GST billing, so the figures match the invoice your customer receives.
Sources
Checked on 17 Oct 2026.
- Notification 9/2025-Central Tax (Rate), 17 September 2025, in force 22 September 2025: cbic-gst.gov.in.
- End of GST compensation cess and 40% rate on tobacco and pan masala from 1 February 2026 (Government notifications reported by PTI, January 2026). Verify
