GST Calculator
Add or remove GST with CGST + SGST breakdown at 5/12/18/28%
Enter an amount to calculate GST
GST rates at a glance
Cess applies additionally on some 28% items — tobacco products attract 5–290% cess depending on the type.
Which GST applies to your transaction?
CGST + SGST
When buyer and seller are in the same state, the GST amount splits equally between CGST (goes to central government) and SGST (goes to state government). A ₹1,000 item at 18% means ₹90 CGST + ₹90 SGST.
Example: A Pune shop selling to a customer in MumbaiIGST
When buyer and seller are in different states, the full rate is charged as IGST. The central government collects it and settles the state share with the buyer's state. The tax amount is identical — only the split mechanism differs.
Example: A Bangalore company billing a client in DelhiHow reverse GST calculation works
Vendors often quote GST-inclusive prices. To find the base amount, divide by (1 + rate/100). A bill of ₹11,800 at 18% GST: base = 11,800 ÷ 1.18 = ₹10,000. The GST component is ₹1,800, split as ₹900 CGST + ₹900 SGST for intra-state sales. This is exactly what our "Remove GST" mode does — toggle it above and enter the total amount.
GST invoicing mistakes that trigger notices
Wrong GST type on invoice
Charging CGST+SGST on an inter-state sale (or IGST on intra-state) is the single most common error. GSTN flags this automatically during return filing, and your buyer cannot claim input tax credit until it's corrected.
Mismatched GSTIN on documents
A single digit wrong in the buyer's GSTIN means the invoice won't appear in their GSTR-2A. They lose ITC, you get a notice. Always verify the 15-digit GSTIN against the GST portal before invoicing.
Applying the wrong HSN/SAC code
Each product and service has a specific classification code that determines the applicable rate. Using an incorrect HSN (goods) or SAC (services) code can result in under-charging GST, which the department treats as short-payment during assessment.
Maximising your Input Tax Credit
ITC is only available when the supplier has filed their GSTR-1 and the invoice reflects in your GSTR-2A/2B. Reconcile monthly — don't wait until the annual return. For FY 2025-26, the deadline to claim ITC for any invoice is 30th November 2026 (or the date of filing the annual return, whichever is earlier). Missing this deadline means permanently forfeiting the credit.
Frequently Asked Questions
What are the current GST rates in India?
India uses four GST slabs: 5% for essential goods like packaged food and medicines, 12% for processed food and business-class air tickets, 18% for most services including restaurants and software, and 28% for luxury items, cars, and tobacco. Some goods like fresh vegetables and milk are GST-exempt.
What is the difference between CGST, SGST, and IGST?
For sales within the same state, GST splits equally into CGST (Central) and SGST (State). For inter-state sales, a single IGST is charged at the full rate, collected by the centre and later settled with the destination state. The total tax amount is the same either way.
How do I reverse-calculate GST from a total amount?
To find the base price from a GST-inclusive amount, divide the total by (1 + GST rate). For example, if an item costs ₹1,180 inclusive of 18% GST: base = 1180 / 1.18 = ₹1,000, and GST = ₹180.
Can I claim input tax credit on GST paid?
Yes, registered businesses can claim ITC on GST paid for business purchases against their output GST liability. The supplier must have filed their return and the purchase must be for business purposes. ITC cannot be claimed on personal expenses, blocked items like motor vehicles (with exceptions), or food and beverages.
Is GST applicable on exports from India?
Exports are zero-rated under GST — you can either export under bond or Letter of Undertaking without paying IGST, or pay IGST and claim a refund later. This ensures Indian exports remain competitive in international markets.
Key Terms
GST
Goods and Services Tax — a unified indirect tax replacing VAT, excise, and service tax across India since July 2017.
CGST
Central GST — the central government's share of GST on intra-state transactions.
SGST
State GST — the state government's share of GST on intra-state transactions.
IGST
Integrated GST — applied to inter-state transactions. The full rate goes to the central government, which settles with the destination state.
Input Tax Credit
Credit claimed on GST paid for business purchases. Reduces your net GST liability.