GST Calculator
Free online GST calculator for India — add or remove GST instantly
The easiest free GST calculator online: enter an amount, pick a rate and get the net price, GST amount, CGST, SGST or IGST and the final total — with the working shown step by step.
Calculate GST now — free
Step-by-step working
How to Calculate GST in Calculator
Pick whichever method suits you — all three give the same answer.
Use this online GST calculator
- Choose Add GST (price without tax) or Remove GST (price with tax).
- Type the amount in rupees.
- Tap the GST rate — 5%, 18%, 40% — or type a custom rate.
- Read the net amount, GST, CGST/SGST or IGST and total instantly.
Key presses on a normal calculator
Tip: the multiplier is always 1 + rate/100 — 1.05 for 5%, 1.18 for 18%, 1.40 for 40%.
The GST formulas to remember
Quick multiplier cheat-sheet
| GST rate | To add GST, × by | To remove GST, ÷ by | GST share of total |
|---|---|---|---|
| 3% | 1.03 | 1.03 | 2.91% |
| 5% | 1.05 | 1.05 | 4.76% |
| 18% | 1.18 | 1.18 | 15.25% |
| 40% | 1.40 | 1.40 | 28.57% |
| 12% (old) | 1.12 | 1.12 | 10.71% |
| 28% (old) | 1.28 | 1.28 | 21.88% |
Worked GST Examples
Exactly the method used in CBSE, TN Board and competitive-exam GST numericals.
A shop sells a pair of shoes for ₹2,000 before tax. Find the price with 5% GST.
- GST = 2000 × 5 ÷ 100 = ₹100
- Total = 2000 + 100
A laptop bill shows ₹59,000 including 18% GST. Find the original price and the GST.
- Net = 59000 ÷ 1.18 = ₹50,000
- GST = 59000 − 50000 = ₹9,000
Goods worth ₹10,000 are sold within Tamil Nadu at 18% GST. Find CGST and SGST.
- Total GST = 10000 × 18 ÷ 100 = ₹1,800
- CGST = SGST = 1800 ÷ 2
Goods worth ₹10,000 are sent from Chennai to Bengaluru at 18% GST. Find the IGST.
- Different states → IGST applies
- IGST = 10000 × 18 ÷ 100
Change the numbers in the calculator above to check your own homework answer.
GST Rates in India — Current Slabs
India's GST structure was simplified on 22 September 2025 (GST 2.0). Here is how the slabs work today.
| Slab | CGST + SGST | Typically applies to |
|---|---|---|
| 0% | 0% + 0% | Nil-rated & exempt essentials |
| 3% | 1.5% + 1.5% | Gold, silver & jewellery |
| 5% | 2.5% + 2.5% | Everyday essentials, many food & daily-use items |
| 18% | 9% + 9% | Standard rate — most goods & services, appliances, electronics |
| 40% | 20% + 20% | Luxury & sin goods — tobacco, aerated drinks, high-end vehicles |
The older 12% and 28% slabs were largely merged into 5% and 18%/40%. They're still used in exam questions and pre-22-Sept-2025 invoices, so this calculator keeps them as options. Always check the HSN/SAC code or the GST portal for the exact rate on a specific item.
GST on common amounts
| Net price | 5% GST → Total | 18% GST → Total |
|---|---|---|
| ₹100 | ₹5 → ₹105 | ₹18 → ₹118 |
| ₹500 | ₹25 → ₹525 | ₹90 → ₹590 |
| ₹1,000 | ₹50 → ₹1,050 | ₹180 → ₹1,180 |
| ₹5,000 | ₹250 → ₹5,250 | ₹900 → ₹5,900 |
| ₹10,000 | ₹500 → ₹10,500 | ₹1,800 → ₹11,800 |
Free GST Calculator Online for India — Add or Remove GST in Seconds
This GST calculator is a free online tool built for Indian shoppers, shopkeepers, freelancers, students and anyone who has ever stared at a bill wondering how much of it is tax. Whether you search for a GST calculator online, an online GST calculator or a free GST calculator, the result is the same: type the amount, choose the rate, and get the GST breakup immediately — no sign-up and no installation.
It works in both directions. Use Add GST when you know the price before tax and want the final invoice amount. Use Remove GST when the price already includes tax and you want to find the original price and the tax portion — handy for checking a restaurant bill, a laptop invoice or an MRP.
As a GST calculator for India, it also splits the tax correctly. For sales within the same state, GST is divided equally into CGST (Central GST) and SGST (State GST). For sales between states, the full amount is charged as IGST (Integrated GST). Rates follow the current 5%, 18% and 40% slabs introduced under GST 2.0, plus 3% for gold, and you can enter any custom rate if your question or invoice needs one.
Students preparing for Accountancy, Business Studies, Commerce or TNPSC exams will find the step-by-step working useful, because it follows the exact method expected in answer sheets. Looking for other tools? Try our speed, distance & time calculator, browse all free online calculators, or get help with Accountancy homework and Business Studies.
← Back to all calculatorsGST calculator — common questions
To add GST, multiply the price by 1 plus the rate divided by 100. For 18% GST on ₹1,000, press 1000 × 1.18 = and you get ₹1,180. To remove GST, divide the GST-inclusive price by the same number: 1180 ÷ 1.18 = ₹1,000. The GST amount is the difference (₹180). Or skip the maths and use the free GST calculator above.
Choose Add GST or Remove GST, enter the amount, select a GST rate (or type a custom one) and choose same-state or other-state supply. The net amount, GST, CGST/SGST or IGST and total update instantly as you type.
Since 22 September 2025 (GST 2.0) the main slabs are 5% and 18%, with 40% for luxury and sin goods, 0% for nil-rated items and 3% for gold and jewellery. The old 12% and 28% slabs were largely merged into these. The exact rate for a product depends on its HSN/SAC code.
Divide the total by (1 + rate/100) to get the net price, then subtract it from the total to get the GST. Example: ₹1,180 including 18% GST → 1180 ÷ 1.18 = ₹1,000 net, GST = ₹180. Switch to the Remove GST tab to do this automatically.
CGST (Central GST) and SGST (State GST) apply together on sales within the same state, each at half the total GST rate. IGST (Integrated GST) applies on sales between two different states and is charged at the full GST rate.
Yes. It is a completely free GST calculator for India with no sign-up, no limits and no data stored — the calculation happens in your browser.
Those slabs were largely retired on 22 September 2025, but many textbooks, exam papers and older invoices still use them. They are marked "old" so you can still solve those questions accurately.
Yes. The add/remove GST logic and CGST-SGST-IGST split are exactly what board and competitive exam numericals test. Use the step-by-step working under the calculator to see the full method, not just the final figure.