What Does This GST Calculator Do?
You have an amount. You need to know the GST on it. That is all this tool is for.
Enter the figure, pick the applicable GST rate, tell it whether your price already includes tax or not, and the calculator shows you the base amount, the GST component, and the total split into CGST and SGST for intra-state, or IGST for inter-state transactions.
No spreadsheet. No formula. No CA needed for a quick check.
This works for business owners raising invoices, freelancers billing clients, accountants verifying numbers, and anyone who just received a quotation and wants to understand the tax portion.
How to Use the GST Calculator: Step by Step
Step 1: Enter Your Amount
Type the price of your goods or services in the Amount field. This can be the price before tax or the price your customer actually pays you will specify this in Step 3.
Step 2: Select the GST Rate
Choose from the updated 2026 GST slabs:
- 0% - Essential items: fresh vegetables, milk, eggs, rice, wheat, books, healthcare
- 5% - Common goods and services: packaged food, soaps, shampoos, butter, economy travel, small restaurants
- 18% - Most goods and services: electronics, mobile phones, TVs, AC, cars (small), most professional services, restaurants with AC, hotel rooms
- 40% - Luxury and sin goods: premium cars, motorcycles above 350cc, aerated drinks, tobacco, gambling, online gaming
- 3% - Gold, finished jewellery, imitation jewellery
- 0.25% - Rough diamonds, unworked precious stones
Note: The 12% and 28% slabs no longer exist under GST 2.0. These were replaced effective September 22, 2025, following the 56th GST Council meeting. Many items previously at 12% moved to 5% or 18%. Items at 28% plus cess now fall under the unified 40% slab.
Step 3: Choose Inclusive or Exclusive
GST Exclusive (most B2B invoices): Your entered amount does not include GST. The calculator adds the tax on top.
GST Inclusive (retail prices, MRP): Your entered amount already has GST baked in. The calculator reverse-calculates and separates the base price from the tax portion.
Step 4: View Your Result
The tool instantly shows:
- Base Amount: price before GST
- GST Amount: the tax component (split as CGST + SGST or IGST)
- Total Amount: the final figure the buyer pays
GST Calculation Formula - How the Math Works
For those who want to verify manually or understand what the calculator is doing:
GST-Exclusive Calculation:
GST Amount = Original Price x GST Rate / 100
Total = Original Price + GST Amount
GST-Inclusive Reverse Calculation:
Original Price = Inclusive Price x 100 / (100 + GST Rate)
GST Amount = Inclusive Price minus Original Price
Worked Example: GST Exclusive at 18%
Service billed at Rs. 10,000. GST rate: 18%. GST = Rs. 10,000 x 18 / 100 = Rs. 1,800 Invoice total = Rs. 11,800 CGST = Rs. 900 | SGST = Rs. 900 (for intra-state) OR IGST = Rs. 1,800 (for inter-state)
Worked Example: GST Inclusive Reverse at 5%
Product sold at Rs. 1,050 inclusive of 5% GST. Original Price = Rs. 1,050 x 100 / 105 = Rs. 1,000 GST Amount = Rs. 1,050 minus Rs. 1,000 = Rs. 50
GST 2.0: What Changed in 2026 and Why It Matters
India's GST system got its biggest update since launch in July 2017. The 56th GST Council meeting on September 3, 2025, introduced what is now called GST 2.0, effective September 22, 2025.
The old five-slab structure (0%, 5%, 12%, 18%, 28%) is gone. Here is what replaced it:
What got cheaper:
- Daily-use items like soaps, shampoos, packaged food moved from 12% to 5%
- Agricultural equipment moved from 12% to 5%
- 33 lifesaving drugs moved to nil (0%)
- Individual health and life insurance premiums moved to 0%
What stayed the same:
- Most professional services remain at 18%
- Electronics like mobile phones, laptops at 18%
What got a new higher rate:
Premium cars, motorcycles above 350cc, tobacco, aerated beverages, online gaming, gambling moved from 28% + cess to a clean 40% rate
Why this matters for your invoices:
If you or your CA is still using 12% or 28% on invoices after September 22, 2025, those invoices are wrong and can attract GST notices. This calculator uses the current 2026 slabs.
Current GST Rate Slab Table: 2026 Updated
| GST Rate |
What It Covers |
| 0% (Nil) |
Rice, wheat, fresh vegetables, milk, eggs, curd, bread, salt, books, newspapers, healthcare services, individual insurance |
| 5% |
Packaged food, soaps, shampoos, hair oil, toothpaste, butter, ghee, fruit juice, economy air travel, small restaurant (no AC), footwear under Rs. 1,000 |
| 18% |
Most services, mobile phones, electronics, laptops, TVs, AC, small cars, motorbikes under 350cc, restaurant with AC, hotel rooms, construction services, professional fees |
| 40% |
Luxury cars, motorbikes above 350cc, aerated drinks, tobacco (after cess settlement), pan masala, online gaming with real money, betting, gambling, horse racing |
| 3% |
Gold, silver, finished jewellery, imitation jewellery |
| 0.25% |
Rough diamonds, unworked precious stones |
This table reflects rates effective September 22, 2025 onward. For specific HSN code classification, visit the official GST portal at gst.gov.in or consult a CA.
CGST, SGST, IGST and UTGST: Explained Simply
There are four types of GST in India. Which one your transaction attracts depends on one thing: are the buyer and seller in the same state or not?
Central GST (CGST)
Collected by the central government when a transaction happens within the same state. Always paired with SGST. Each is charged at half the total GST rate.
Example: 18% intra-state GST = 9% CGST + 9% SGST
State GST (SGST)
Collected alongside CGST by the state government. Revenue goes to the state where the sale happened.
Integrated GST (IGST)
Charged on transactions between two different states, and on imports. The central government collects it and sends the destination state's share. Charged at the full GST rate, not split.
Example: 18% inter-state GST = 18% IGST (no CGST or SGST)
Union Territory GST (UTGST)
Works exactly like SGST but applies in India's union territories Chandigarh, Dadra and Nagar Haveli, Daman and Diu, Lakshadweep, Puducherry, Ladakh, and Andaman and Nicobar Islands.
Who Needs a GST Registration in India?
You are legally required to register for GST if your annual turnover crosses:
- Rs. 40 lakh: if you supply goods (Rs. 20 lakh in special category states)
- Rs. 20 lakh: if you supply services (Rs. 10 lakh in special category states)
Below the threshold, registration is optional. But many freelancers, consultants, and agencies register voluntarily, because their clients are GST-registered companies that need to claim Input Tax Credit (ITC) on the invoice. Without your GSTIN on the bill, they cannot claim ITC and may refuse to work with you.
Certain categories must register regardless of turnover: e-commerce sellers, businesses making inter-state supplies, and those liable under reverse charge.