Free GST calculator
GST Calculator for India: add or remove GST
Type an amount, pick the GST rate and see the taxable value, CGST and SGST or IGST, and the total. Works for exclusive and inclusive prices, exact to the paisa.
- Inclusive and exclusive
- CGST + SGST or IGST
- Free, no sign-up
The amount is before GST. GST is added on top.
Seller and place of supply in the same state: CGST + SGST (or UTGST), half each.
- Taxable value
- ₹1,000.00
- CGST @ 9%
- ₹90.00
- SGST @ 9%
- ₹90.00
- Total GST @ 18%
- ₹180.00
- Total amount
- ₹1,180.00
GST = ₹1,000.00 × 18 ÷ 100 = ₹180.00.
Worked out to the paisa, rounded half-up. Check the rate for your HSN/SAC code with your CA.
What this GST calculator does
Add or remove GST
Work forward from a price before tax, or backward from an MRP or any price that already includes GST.
CGST + SGST or IGST
Pick within state or other state and see the tax split the way it goes on the invoice.
Every rate, plus custom
0%, 0.25%, 3%, 5%, 12%, 18%, 28% and 40% are one tap away, and any other rate can be typed in.
Exact to the paisa
The maths is done in whole paise, so the taxable value and the tax always add up to the total.
GST calculation formula, with worked examples
A GST calculator does one of two things. It either adds GST to a price that does not include tax yet (an exclusive price), or it takes GST out of a price that already includes it (an inclusive price). The formulas are short:
Add GST (exclusive): GST = taxable value × rate ÷ 100. Total = taxable value + GST.
Remove GST (inclusive): taxable value = inclusive price × 100 ÷ (100 + rate). GST = inclusive price − taxable value.
The examples below are what the calculator above shows for the same inputs. Try them to check your own working.
GST calculation examples
| What you have | Working | Result |
|---|---|---|
| ₹1,000 before tax, 18%, within the state | 1,000 × 18 ÷ 100 = 180, split in half | CGST ₹90 + SGST ₹90, total ₹1,180 |
| ₹2,500 before tax, 5%, to another state | 2,500 × 5 ÷ 100 = 125 | IGST ₹125, total ₹2,625 |
| 12 pieces at ₹45 each, 18%, within the state | 12 × 45 = 540; 540 × 18 ÷ 100 = 97.20 | CGST ₹48.60 + SGST ₹48.60, total ₹637.20 |
| ₹1,050 including 5% GST | 1,050 × 100 ÷ 105 = 1,000 | Taxable value ₹1,000, GST ₹50 |
| ₹100 including 18% GST, within the state | 100 × 100 ÷ 118 = 84.745… → 84.75 | Taxable ₹84.75, GST ₹15.25: CGST ₹7.63 + SGST ₹7.62 |
The last row shows why the halves can differ by a paisa: ₹15.25 cannot be split into two equal amounts, so the calculator puts the odd paisa on CGST and the two still add up to the tax exactly.
Inclusive vs exclusive GST: which one do you have?
A price is exclusive of GST when tax will be added on the bill. Wholesale rate lists, quotations to businesses and most purchase orders are written this way: "₹450 + GST".
A price is inclusive of GST when the tax is already inside it. The MRP printed on a packet is inclusive ("incl. of all taxes"), and so are most counter prices in a retail shop. To put an inclusive price on a tax invoice you have to work backwards to the taxable value, because the invoice shows the taxable value and the tax separately.
The common mistake is taking 18% of an inclusive price. On ₹1,180 that gives ₹212.40, but the real tax inside ₹1,180 is ₹180. Use "Remove GST" for any price that already includes tax.
CGST and SGST vs IGST in the GST calculator
GST is one tax collected in two ways. When the supplier and the place of supply are in the same state, the tax is split equally: half is CGST (to the Centre) and half is SGST (to the state), or UTGST in a union territory without its own legislature. At 18% that is 9% + 9%.
When the place of supply is in another state, the whole tax is IGST. Exports and supplies to SEZ units are also charged as inter-state supplies. The amount of tax is the same in both cases; only the heads it is booked under change, which matters for your returns and for the buyer's input tax credit.
If you are registered under the composition scheme you do not charge GST to the buyer at all, and you issue a bill of supply instead of a tax invoice. The difference is explained in bill of supply vs tax invoice.
Rounding GST on an invoice
Work tax out to the paisa on each line, then total it. This calculator rounds half-up at every step (₹0.005 becomes ₹0.01) and never uses floating-point maths, which is why its CGST and SGST always add up to the total GST.
Many businesses then round the invoice total to the nearest rupee and show the difference as a separate "Round off" line, so the taxable value and tax on the invoice stay exact. The GST law separately says that tax, interest and other amounts payable are rounded to the nearest rupee when you pay them. How your own invoices should round is a question for your CA; what matters most is doing it the same way every time.
GST rates after the September 2025 change
From 22 September 2025 the GST Council moved most goods and services into two main rates, 5% and 18%, and added a 40% rate for a short list of goods. Most items that were at 12% or 28% moved into the new slabs, but you will still see the old rates on earlier invoices and on a few items. Special rates such as 3% and 0.25% for precious metals and stones continue.
The calculator does not decide the rate for you. Find the rate for your HSN or SAC code, pick it above, or type it with "Custom". When the rate is not clear, confirm it with your CA before you bill.
To bill with these numbers instead of copying them by hand, the free GST invoice generator builds a tax invoice PDF with the same split. For every bill, customer and item in one place, see VyapRise GST billing software.
GST calculator: common questions
How do I calculate GST on an amount?
Multiply the amount before tax by the GST rate and divide by 100. For ₹1,000 at 18%, GST is ₹180 and the total is ₹1,180. Within your state, split the ₹180 into ₹90 CGST and ₹90 SGST; to another state, charge the full ₹180 as IGST.
How do I remove GST from an inclusive price?
Divide the inclusive price by (100 + rate) and multiply by 100 to get the taxable value. The GST is the inclusive price minus the taxable value. For ₹1,180 at 18%: 1,180 × 100 ÷ 118 = ₹1,000 taxable value and ₹180 GST. Choose "Remove GST" in the calculator to do this.
When do I charge CGST and SGST, and when IGST?
Charge CGST plus SGST (or UTGST in a union territory) when your business and the place of supply are in the same state. Charge IGST when the place of supply is in another state, and on exports and supplies to SEZ units. The total tax is the same either way; only the split changes.
Which GST rate applies to my product?
It depends on the HSN code of the goods or the SAC of the service. Since 22 September 2025 most goods fall under 5% or 18%, with a 40% rate for a short list of goods, but there are exceptions and special rates. Look up your HSN/SAC in the official rate notifications or ask your CA, then pick that rate here.
Is this GST calculator free, and is my data saved?
Yes, it is free with no sign-up. The calculation runs in your browser and nothing you type is sent to our server or stored.
Guides on this topic
Plain-language explainers, written in Hindi.
- New GST Slab 2026: 5%, 18%, 40% की पूरी GST Rate List2026 में GST के मुख्य स्लैब 5% और 18% हैं, और कुछ चुनिंदा luxury व de-merit चीज़ों पर 40%। ये 22 सितंबर 2025 से लागू हैं, जब 12% और 28% के स्लैब हटाए गए। सोने-चाँदी पर 3% और कच्चे हीरों पर 0.25% जैसी विशेष दरें जारी हैं। PIB रिलीज़ के अनुसार 57th GST Council meeting में स्लैब नहीं बदले।
- 57th GST Council Meeting: 8 अक्टूबर 2026 के बड़े फैसले8 अक्टूबर 2026 को हुई 57th GST Council meeting में GST स्लैब नहीं बदले; सिर्फ़ कुछ स्पष्टीकरण और चुनिंदा रेट बदलावों की सिफ़ारिश हुई। फ़ोकस प्रक्रिया पर रहा: ₹5 करोड़ तक टर्नओवर वालों के लिए महीने के अंदर देर से भरे रिटर्न पर लेट फीस माफ़ी, ₹10,000 से कम टैक्स पर नोटिस नहीं, जनरल पेनल्टी ₹25,000 से घटाकर ₹10,000, गिरफ़्तारी का प्रावधान (धारा 69) हटाना, प्रॉसिक्यूशन की सीमा बढ़ाकर ₹5 करोड़ करना, और free samples, insurance जैसी चीज़ों पर ITC खोलना। ये सिफ़ारिशें हैं — नोटिफ़िकेशन या कानून में बदलाव के बाद ही लागू होंगी।
Related tools and guides
- GST billing softwareGST invoices with CGST, SGST or IGST worked out from the place of supply.
- Free GST invoice generatorMake one tax invoice PDF with your logo and UPI QR, no sign-up.
- Bill of supply vs tax invoiceWhich document a composition dealer issues, and why it carries no GST.
- GST invoice mandatory fieldsEverything a tax invoice must show, field by field.
- Free quotation generatorSend a quote with GST shown line by line.
Let every bill work out its own GST
A free VyapRise account makes GST invoices with CGST, SGST or IGST picked from the place of supply, keeps up to 30 items and 10 customers, and moves stock with every sale. Pro adds purchase bills, receipts, GSTR-1, GSTR-3B and HSN summary reports, with a 7-day free trial.
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