GST Calculator
Got a price and need to know the GST on it? Or a final amount and need to strip the tax out? Type the number and get the answer in two seconds.
Price Breakdown
| Base Price: | ₹0.00 |
| CGST (9%): | ₹0.00 |
| SGST (9%): | ₹0.00 |
| Total Price: | ₹0.00 |
What is GST?
Before July 2017, India ran on a mess of overlapping taxes: VAT, Service Tax, Excise Duty, Entry Tax, and more. Different states had different rates. A truck crossing state borders had to stop and deal with paperwork at each checkpoint. GST (Goods and Services Tax) replaced all of that with a single unified tax on July 1, 2017. Today, the same rates apply across the country: 0%, 5%, 12%, 18%, or 28%, depending on what the product or service is.
Every GST transaction splits the tax in two. CGST goes to the Central Government and SGST goes to the State Government, each taking exactly half the total rate. Buy something in the same state you are in, and you pay CGST plus SGST. Buy from a seller in another state, and you pay IGST instead, which is the full rate combined. The amount you pay is identical either way.
How to Use GST Calculator?
Two modes, two steps each:
- Pick your mode: "Add GST" if you are starting from the base price. "Remove GST" if you have a GST-inclusive total and want to know what the base was.
- Type the amount: Enter the rupee figure you are working with
- Select the rate: Pick 5%, 12%, 18%, or 28%. There is also a custom field if your product falls at a different rate.
- Read the output: You get the total price, the exact GST amount, and the CGST plus SGST split
Switching between modes is instant. No page reload, no form submission.
GST Calculation Formula
To add GST to a base price:
GST Amount = (Original Price × GST Rate) ÷ 100
Total Price = Original Price + GST Amount
Worked example, adding 18% GST to Rs.10,000:
- GST Amount = (₹10,000 × 18) ÷ 100 = ₹1,800
- Total Price = ₹10,000 + ₹1,800 = ₹11,800
- CGST = ₹900 (9%)
- SGST = ₹900 (9%)
To find the base price when GST is already included:
Base Price = Total Price ÷ (1 + GST Rate/100)
GST Amount = Total Price - Base Price
Worked example, removing 18% GST from Rs.11,800:
- Base Price = ₹11,800 ÷ 1.18 = ₹10,000
- GST Amount = ₹11,800 - ₹10,000 = ₹1,800
- CGST = ₹900 (9%)
- SGST = ₹900 (9%)
GST Rates in India
GST does not charge the same rate on everything. The rate depends on what category the product falls into:
- 0% (Nil): Fresh milk, vegetables, bread, salt, jaggery. Daily essentials that most households cannot do without.
- 5%: Edible oils, sugar, tea, coffee, coal, medicines, and life-saving drugs. Still affordable items kept at a low rate.
- 12%: Processed foods, computers, butter, ghee, and basic mobile phones. A middle-ground category.
- 18%: The most common rate. Covers soaps, toothpaste, IT services, restaurant bills, capital goods, and a long list of other items you encounter every day.
- 28%: Air conditioners, cars, cigarettes, aerated drinks, and pan masala. Luxury and sin goods carry the highest rate.
On top of 28%, certain goods carry an additional cess. Tobacco products and cars, for example, attract cess charges over and above the base GST rate.
CGST, SGST, and IGST Explained
CGST: Goes to the Central Government. Exactly half the total GST rate. Applies when buyer and seller are in the same state.
SGST: Goes to the State Government. Also exactly half the total GST rate. Collected alongside CGST on intra-state transactions.
IGST: Applied on inter-state transactions, where buyer and seller are in different states. The Central Government collects the full rate and later shares the state's portion with the destination state.
Same-state purchase (Delhi buyer, Delhi seller):
- Product Price: ₹1,000 | GST Rate: 18%
- CGST: 9% = ₹90 (to Central Govt)
- SGST: 9% = ₹90 (to Delhi Govt)
- Total: ₹1,180
Cross-state purchase (Delhi buyer, Maharashtra seller):
- Product Price: ₹1,000 | GST Rate: 18%
- IGST: 18% = ₹180 (to Central Govt initially)
- Total: ₹1,180 | Later distributed between Centre and State
Benefits of GST
GST fixed several real problems with the old system:
- Single tax across India: One registration, one rate, one compliance framework instead of navigating different state tax laws
- No more tax-on-tax: The old system taxed goods at multiple stages without giving credit. GST eliminates that cascading effect entirely
- Online compliance: Everything happens on the GST portal. No running between government offices for registrations and filings
- Better tracking: Every transaction in the system is matched digitally. This has significantly reduced opportunities for tax evasion
- Input Tax Credit: Businesses offset the GST they paid on purchases against the GST they collect from customers. Only the net amount goes to the government
- Faster goods movement: Trucks no longer wait at state borders for tax paperwork. Logistics has become meaningfully more efficient
- Cheaper goods in several categories: Goods that were taxed multiple times under the old system came down in price after GST removed the cascading layers
GST Exemptions and Special Categories
What pays zero GST:
- Fresh milk, curd, buttermilk
- Fresh vegetables and fruits
- Unbranded wheat, rice, flour
- Salt, jaggery
- Educational services (schools, colleges)
- Healthcare services (hospitals, clinics)
Reverse Charge Mechanism (RCM): Normally the supplier collects and pays GST. Under RCM, this flips: the buyer pays the GST directly to the government. This applies in specific situations:
- Buying services from an unregistered supplier
- Importing services from outside India
- Specific notified goods such as cashew nuts and tobacco leaves
Composition Scheme: If your annual turnover is below Rs.1.5 crore, you have the option to pay a flat GST rate of 1% to 5% and file quarterly instead of monthly. This reduces paperwork significantly for small businesses, but you give up the ability to claim Input Tax Credit.
Frequently Asked Questions About GST
How do I calculate GST on a product price?
Adding GST is straightforward. Multiply the base price by the GST rate, divide by 100, and add that number to the original price. On Rs.5,000 at 18%: GST comes to Rs.900, making the total Rs.5,900. Going the other way, divide the GST-inclusive total by (1 + rate divided by 100). Rs.5,900 divided by 1.18 gives you the base price of Rs.5,000. The CGST and SGST are each half the total GST. At 18%, CGST is 9% and SGST is 9%, both applied to the base price.
What is the difference between GST inclusive and exclusive?
GST exclusive means the price tag shows the base amount before tax. GST gets added on top when you pay. This is standard in B2B invoices and trade transactions. GST inclusive means the tax is already baked into the number you see. Retail prices and MRP tags in India are almost always GST inclusive. When a quote says "plus GST", the price is exclusive. When the bill says "inclusive of all taxes", the GST is already inside that number. Knowing which one applies before you sign a purchase order or quote a price to a client saves you from real errors.
What is CGST and SGST in GST?
When you buy something from a seller in the same state, the GST splits into two equal halves. Half goes to the Central Government as CGST, and the other half goes to your state government as SGST. At 18% GST, that is 9% CGST and 9% SGST. When you buy from a seller in a different state, the split does not happen at your end. You pay IGST at the full rate, and the Central Government later distributes the state's share to the destination state. Your total tax outgo is identical in both cases.
Which GST rate applies to my purchase?
Fresh milk, vegetables, unbranded grains, and bread sit at 0%. Sugar, tea, edible oils, coal, and most medicines are taxed at 5%. Computers, processed foods, and butter fall under 12%. The 18% bracket is the broadest and covers soaps, toothpaste, IT services, restaurants, and hundreds of other everyday goods and services. Cars, air conditioners, cigarettes, and aerated drinks attract 28%, and some of these also carry an additional cess on top. When in doubt, check the HSN code printed on your invoice. That code maps directly to a specific GST rate.
How to calculate GST percentage from total amount?
If you have both the base price and the total, the formula is: subtract the base from the total, divide by the base, and multiply by 100. Rs.10,000 base, Rs.11,800 total gives 18%. If you only have the final price and need to work backward, divide by 1.05, 1.12, 1.18, or 1.28 depending on which rate you think applies, and compare the result to the invoice. Every GST invoice is legally required to show the rate and the breakup, so checking the original document is always the cleanest approach.
Do I need to pay GST on online purchases?
Yes, GST applies to online purchases exactly as it does offline. The rates are the same, the rules are the same. E-commerce platforms like Amazon and Flipkart collect GST on behalf of their sellers and deposit it with the government. The price you see on most product listings already includes GST. As a regular consumer you pay the GST and that is the end of it. If you run a business and the purchase was for business use, download the invoice and claim the Input Tax Credit. Do not skip downloading invoices for business purchases.
When should a business register for GST?
Registration becomes mandatory once your annual turnover crosses Rs.40 lakh for most states, or Rs.20 lakh for special-category states in the Northeast and hills. If you sell across state lines or through an e-commerce platform, registration is mandatory from day one regardless of turnover. Registering voluntarily before crossing the threshold makes sense when your customers are businesses that need to claim Input Tax Credit from you. Without a GST number, you cannot give them that, which makes your pricing less attractive in B2B transactions. Skipping registration when it is required carries a penalty of Rs.10,000 or 10% of the tax owed, whichever is higher.
What is Input Tax Credit (ITC) in GST?
Input Tax Credit is the mechanism that stops GST from being a tax on a tax. When you buy raw materials and pay Rs.1,800 in GST, then sell the finished product and collect Rs.3,600 in GST, you only deposit the difference of Rs.1,800 to the government. The Rs.1,800 you already paid offsets what you collected. ITC does not apply to everything. Personal expenses, motor vehicles in most situations, and food and beverages consumed in-house do not qualify. The restriction is practical: ITC is for business inputs that go into making or selling something, not for personal consumption dressed up as a business expense.
How to file GST returns?
Regular GST filers submit two main returns each month. GSTR-1 covers outward sales and is due by the 11th. GSTR-3B is a summary return with tax payment, due by the 20th. If your annual turnover is below Rs.5 crore, you qualify for QRMP, which means quarterly returns but you still pay tax monthly. The GST portal at gst.gov.in handles all of this online. You upload your invoices, the system auto-populates some fields, you verify, pay digitally, and submit using DSC or EVC. Filing late costs Rs.50 per day per return, capped at Rs.5,000, plus 18% annual interest on whatever tax amount stayed unpaid.
What happens if I don't pay GST on time?
Missing your GST payment date immediately starts the clock on interest at 18% per annum, calculated daily from the due date. Late filing fees add Rs.100 per day per return, combining CGST and SGST, and cap at Rs.5,000 total per return. Repeated defaults are treated more seriously. The GST department has powers to attach your bank account and seize assets without going through a lengthy court process. For evasion above Rs.5 crore, criminal prosecution with imprisonment up to 5 years is on the table. Most of these consequences start from a simple missed payment date, which is why keeping an auto-debit or calendar reminder for the 20th of each month is worth setting up.