Business
How to Calculate GST: Add or Remove GST from Any Price
The two GST formulas with worked examples, the mistake most people make, the CGST/SGST split and the slabs after the 2025 reform.
By Team Vind · Updated · 4 min read
Whether you're making an invoice or checking a bill, GST comes down to two calculations: adding GST to a price, and taking it out of a price that already includes it. The second one is where most people go wrong.
Adding GST to a price
Price with GST = price × (1 + rate ÷ 100)
₹10,000 at 18%: GST = ₹10,000 × 18 ÷ 100 = ₹1,800, so the total is ₹11,800.
| Rate | GST on ₹10,000 | Total |
|---|---|---|
| 5% | ₹500 | ₹10,500 |
| 18% | ₹1,800 | ₹11,800 |
| 40% | ₹4,000 | ₹14,000 |
Removing GST from a total
Price before GST = total ÷ (1 + rate ÷ 100)
A bill of ₹1,180 including 18% GST: ₹1,180 ÷ 1.18 = ₹1,000 before tax, and the GST is ₹180.
Try it: GST Calculator
GST Breakdown
- Net price₹10,000(85%)
- GST₹1,800(15%)
CGST, SGST and IGST
The total tax is the same; what changes is who receives it.
- Sale within a state: split half and half. 18% becomes 9% CGST (Centre) + 9% SGST (state). On ₹10,000, that's ₹900 + ₹900.
- Sale to another state: the full 18% is charged as IGST, ₹1,800.
- Union territories without a legislature: UTGST replaces SGST.
GST rates after the 2025 reform
From 22 September 2025, the old 12% and 28% slabs were mostly folded into two main rates, 5% and 18%, with a special 40% rate for luxury and sin goods. Examples:
| Rate | Examples |
|---|---|
| 0% (exempt) | Fresh vegetables, fruit, milk, curd, eggs, bread, unbranded atta; health and life insurance for individuals |
| 5% | Packaged food items, soaps, toothpaste, hair oil, many medicines, economy hotel rooms, restaurants |
| 18% | Most other goods and services: electronics, ACs, cars below the luxury limits, telecom, banking and professional services |
| 40% | Luxury and sin goods, such as aerated sugary drinks, larger cars and motorcycles above 350 cc |
| 3% | Gold, silver and jewellery |
Reverse calculation shortcuts
- GST included at 18%: GST = total × 18 ÷ 118.
- GST included at 5%: GST = total × 5 ÷ 105.
- GST included at 40%: GST = total × 40 ÷ 140.
Pricing products as well? The profit margin calculator and markup calculator work on the price before GST.
Frequently asked questions
How do I calculate 18% GST on ₹1,000?
₹1,000 × 18 ÷ 100 = ₹180, so the total is ₹1,180.
How do I find GST from an inclusive amount?
Multiply the total by rate ÷ (100 + rate). For 18%: total × 18 ÷ 118.
Are 12% and 28% GST rates still in use?
Most items moved to 5% or 18% from 22 September 2025, and luxury and sin goods to 40%. Check the CBIC schedule for any exceptions.
Is GST charged on MRP?
MRP already includes GST. Shops can't add GST on top of MRP.
These results are estimates for planning only, not financial, investment or tax advice. Rates and rules change, and your bank, fund house or employer may calculate slightly differently. Check with them or a qualified adviser before you decide.
Sources
- CBIC: GST rates for goods and services
- GST Council: 56th meeting recommendations (rates from 22 September 2025)
Last reviewed: 10 October 2026