GST Calculator
Add or remove GST from any amount, with CGST/SGST breakdown. Free, instant.
Final Amount (incl. GST)
₹1,180
₹180
Total GST
₹90
CGST
₹90
SGST
CGST/SGST split shown assumes an intra-state transaction (equal split). For inter-state transactions, the full GST amount is charged as IGST instead.
GST (Goods and Services Tax) calculations come up constantly for anyone running a business, freelancing, or just double-checking a bill — whether that's adding GST to a price before invoicing a client, or working backward from a GST-inclusive price to find the base amount and tax paid.
This calculator handles both directions: 'Add GST' takes a base amount and shows the GST amount plus the final price, while 'Remove GST' takes a GST-inclusive amount and works backward to show the base price and the tax portion — useful when a receipt only shows the final total.
For intra-state transactions, GST is typically split equally between CGST (Central GST) and SGST (State GST), which this tool shows automatically. For inter-state transactions, the full amount is instead charged as IGST — a quick note on the results reminds you which applies.
Step-by-step instructions
- 1
Choose Add GST or Remove GST
Add GST if you have a base price and want the tax-inclusive total. Remove GST if you have a final price and want to find the base amount.
- 2
Enter the amount
Type in the base amount (Add mode) or the GST-inclusive amount (Remove mode).
- 3
Select or type the GST rate
Use one of the common rate buttons (5%, 12%, 18%, 28%) or enter a custom rate.
- 4
Read the results
See the final amount, total GST, and the CGST/SGST split.
Common use cases
Creating an invoice for a client
Calculate the GST-inclusive total to charge based on your service or product price.
Checking a bill or receipt
Work backward from a final price to see exactly how much of it was GST.
Pricing a product for sale
Figure out what base price to set so the final GST-inclusive price hits a specific number.
Comparing GST rates
See how different GST slabs (5%, 12%, 18%, 28%) affect the final price of the same base amount.
Tips for best results
- The CGST/SGST split shown assumes an intra-state sale (buyer and seller in the same state) — for inter-state transactions, the full GST amount is charged as IGST instead, not split.
- When removing GST from a price, remember the base amount isn't simply the final price minus the GST percentage of the final price — the formula divides by (100 + rate), not just subtracts the percentage.
- Double-check which GST slab applies to your specific goods or service, since rates vary by category under GST rules.
Frequently asked questions
What's the difference between CGST, SGST, and IGST?
CGST and SGST apply to transactions within the same state and are split equally, each collected by the central and state government respectively. IGST applies to inter-state transactions and is collected as a single combined tax.
How do I calculate GST backward from a final price?
Use 'Remove GST' mode — enter the GST-inclusive final amount, and the tool calculates the original base price and the GST portion using the formula: base = final × 100 ÷ (100 + rate).
Why isn't the base amount just the final price minus the GST percentage?
Because the GST percentage in 'Remove' mode applies to the base amount, not the final amount — dividing by (100 + rate) correctly reverses the calculation, while simply subtracting the percentage from the final price would give a slightly wrong answer.
Is my data stored anywhere?
No — every calculation happens in your browser. Nothing you enter is sent to a server or saved.
Does this tool file GST returns or connect to the GST portal?
No — this is a standalone calculator for quick math only. It doesn't file returns or connect to any government system.