GST Calculator (India)
Calculate Indian GST on any amount at 5%, 12%, 18% or 28% slabs. Splits into CGST + SGST for intra-state or IGST for inter-state. Works both ways: GST-exclusive (add tax) and GST-inclusive (back-calculate from a final price). Everything happens in your browser: nothing is uploaded.
🔒 100% private, calculated locally in your browser. Nothing is uploaded.
When to use this
Three common moments when an Indian solopreneur or freelancer needs a GST split fast:
- Quoting a client: the rate they need to see is GST-exclusive (your work) plus the GST line item. This shows them the real total.
- Reading an invoice or receipt: the price is GST-inclusive. The calculator works backwards to show what the supplier actually charged for the goods or service vs the tax.
- Filing returns: the CGST + SGST or IGST split decides which fields on GSTR-1 and GSTR-3B the tax flows into. Get the split wrong and reconciliation breaks.
How the math works
Exclusive (add): tax = amount × rate / 100. Final = amount + tax. For intra-state, CGST = SGST = tax / 2. For inter-state, IGST = tax.
Inclusive (extract): base = total / (1 + rate/100). Tax = total - base. Split the same way as above.
The numbers are rounded to two decimals on display. Internal math runs at full float precision so a copy-paste into an invoice will reconcile to within a paisa.
Quick GST slab cheat sheet
- 0%: essential unbranded food, fresh vegetables, milk, education and healthcare services.
- 5%: packaged food, footwear under Rs.1000, economy air travel, restaurants without AC.
- 12%: processed food, computers, business class air travel, branded apparel above Rs.1000.
- 18%: most services (software, consulting, design, marketing), AC restaurants, electronics, telecoms.
- 28%: luxury goods, automobiles, tobacco, sin goods. Often plus a compensation cess.
Your specific HSN (goods) or SAC (services) code decides the rate. The CBIC rate finder at cbic-gst.gov.in is the authoritative source. When in doubt, your CA.
Frequently asked questions
Is my data sent anywhere?
No. Everything happens entirely in your browser as you type. No amount, no rate, no calculation is ever uploaded or stored on a server. Safe for client work, quotes and private invoices.
What is the difference between CGST, SGST, and IGST?
For an intra-state sale (buyer and seller in the same state), GST is split equally into CGST (paid to the central government) and SGST (paid to the state government). For an inter-state sale (different states or to a UT), the full amount is charged as IGST, which the central government later distributes. The calculator lets you pick which case applies.
What is the difference between GST-inclusive and GST-exclusive?
GST-exclusive means the amount you enter is the base price and GST is added on top (the customer pays more than what you entered). GST-inclusive means the amount you enter is the final price already including GST (you back-calculate the base and the tax portion). Use exclusive when quoting; use inclusive when working from a receipt or MRP.
Which GST slab applies to what?
India has five main GST slabs. 0% covers essentials like unbranded grains, milk and vegetables. 5% covers items like packaged food, footwear under Rs.1000 and economy travel. 12% covers items like processed food, computers and business class travel. 18% is the standard rate for most services, software, electronics and restaurants. 28% covers luxury goods, automobiles and tobacco. When in doubt, check the official CBIC rate finder or ask your CA for your HSN/SAC code.
Does this work for reverse charge or composition scheme?
This calculator does the core split, base + CGST + SGST or IGST. Reverse charge (where the buyer pays GST directly to the government) and composition scheme (a flat 1% to 6% on turnover for small businesses) need different handling and are outside the scope of a quick calculator. Talk to your CA before assuming either applies to your invoice.